[GXRUser]

Well, there is quite a difference in size, weight and comfort. Even the smaller DA Limiteds, when clamped on the K to M adapter are big, clumsy, uncomfortable and tedious to use. The 40mm pancake might be the nicest of those. 42mm screwmount lenses aren't quite as bad with the m42 adapter but still, it's much clumsier with those, too.
For example, I have tried a 135mm Leica R lens with the LR to LM adapter, but the experience was not that pleasant, nor usable. The lens is long and heavy, heavier than the GXR and the module together, and handheld shooting felt a bit daft. Not much smarter with a tripod, either. A reasonably fast 50 or 58mm m42 or LR lens wasn't much better, either. It''s still an awkward chunk of glass and metal uncomfortably far from the body itself, although a bit more usable.

I ended up selling the R lens and buying a native M lens to replace it, and the difference was like night and day, even though I lost half a stop of speed, and a little bit of focal length. Shooting with the short SLR telephoto was tedious and hard to do handheld, but quite enjoyable with the native one. Same with wideangles and standard lenses. I still have and sometimes use the m42 to M adapter and a couple of m42 lenses but, I am in the process of gradually replacing all of them with proper native M lenses. The m42 lenses are much better and nicer with typical (D)SLR bodies.

The GXR really is a fully digital rangefinder. Sort of. Not just a small mirrorless DSLR substitute. Putting a huge DSLR lens (along with a chunky adapter) into the GXR defeats the whole purpose of the system. IMO, anyway.
Besides, the GXR M module has been designed with the typical (symmetric) rangefinder lenses in mind and optimised for them, unlike the other mirrorless systems. That's why the M module has a real M bayonet to begin with, the sensor has no AA filter, and apparently the IR filter is also thinner than usual, much like in the digital Leica M bodies, and unlike in other mirrorless bodies.
Therefore it makes more sense (again, IMO) to use the GXR M-module as a digital M-mount rangefinder with the classic M-mount rangefinder lenses, rather than as an awkward mirrorless body with chunky adapters and all sorts of lenses designed for entirely different systems. Vice versa, it sort of makes more sense to use the classic M mount lenses in either a real Leica or the GXR, rather than in other mirrorless systems with an adapter. A non-native lens with an adapter is always a compromise, and in the case of the GXR, perhaps more so than with some other mirrorless systems.

In other words, whilst it's possible (and maybe cheaper) to use the GXR mount (+ K-M adapter) as a K-01 substitute, I for one don't recommend it. At least not as a permanent solution. It's not particularly fun or comfy, either. Want to use the old K lenses with a small mirrorless camera, buy a K-01. It's cheaper, too, these days.

-just my 2c, and I'll come up with my lens recommendations in another, hopefully shorter post.

I agree with your statements. The only issue for me is that the GXR has an option for an EVF where the K-01 does not. This does not matter in the studio, but it is a real issue outside.

I also agree that I find native M Mount lenses balance best on the GXR due to size. I especially like the Voigtlander 25mm Snapshot Skopar, a Leica Screw Mount lens.

For anyone just getting a GXR with M Mount module, if you already own DA lenses, then it is more economical to begin with a Novoflex to Leica M adapter. Once one is committed to it, then begin to add native M Mount lenses.

I recommend the Novoflex because it should have the tightest tolerances and have the closest accuracy with focus to infinity. Others (Kipon, fotodiox) will allow a lens to focus to infinity before the infinity setting. Rayqual also has high quality and tolerances.

[EchoOscar]

I agree with your statements. The only issue for me is that the GXR has an option for an EVF where the K-01 does not. This does not matter in the studio, but it is a real issue outside.

Well, it was kinda my point that even K-r, for example, would make more sense with a set of K/DA lenses than GXR+M module. Especially so if you need a VF. It doesn't even cost much more than the K-01 these days. Again, shooting with a GXR + M module + adapter + DA lens is awkward, tedious and clumsy. It defeats the purpose of both the GXR system and the DA lenses. It combines the worst of each system and, it isn't terribly practical, either, is it. So why bother? Isn't that trying to save money in all the wrong places?

It may also be a matter of taste, at least partially. But my advice would be not to go for the M module, unless you're prepared to buy native lenses for it, too. In such a case, I'd start with the A12 and A16 modules instead.

Anyway, I agree that one of the biggest blunders Pentax did with the K-01 was to let it out in the world without even an option for an EVF. It was all about form over function.

For anyone just getting a GXR with M Mount module, if you already own DA lenses, then it is more economical to begin with a Novoflex to Leica M adapter.

Yes, it may be more economical, but other than that, it doesn't make much sense. Like I said, with a set of existing DA lenses, it would make more sense, and be more economical, too, to begin with a native body for those lenses, like a K-01, K-r or K-x, or even K-7. All reasonably affordable these days. I'd recommend against getting just the GXR M mount module, if your plan is to use mostly your DSLR lenses with it.

FWIW, I do realize this is a matter of personal preferences, and that there's nothing wrong with your approach per se. If it's working for you, all the better. In fact, I used to think very much like you do when I first started with the GXR system. But now, after some hands-on experience, meh, not any longer. I came to the conclusion that it's not worth the hassle. I'd rather get something else for my DSLR lenses. Especially for those without any aperture ring.

That's why I wrote that somewhat assertive sounding statement to begin with. To help others to avoid the adapter mess, and go straight to the bliss of using an inexpensive Leica substitute. Because that's what the GXR Mount really is. It's not a K-01 with an optional EVF.

But one little disclaimer, though...

I recommend the Novoflex because it should have the tightest tolerances and have the closest accuracy with focus to infinity. Others (Kipon, fotodiox) will allow a lens to focus to infinity before the infinity setting. Rayqual also has high quality and tolerances.

Agreed. Novoflex adapters are generally good stuff, and it shows in their prices, too. Although I'm reasonably content with my two Fotodiox adapters ("American Novoflex"), so far.

In other words, yes, having said all that, I do still own two lens adapters for the M module.
Albeit I hardly ever use them any longer. But still, I do own one m42 adapter, which I use for two very special lenses, not available as native M lenses, and one Leica R adapter, which I also bought for one special lens. Although nowadays it's just collecting dust in my gear shelf, as well as the m42 adapter, too, most of the time.

[EchoOscar]

Okay, I sort of promised to add my own recommendations for M mount lenses.
Well, for starters, if you can afford them and find them, the Minolta M-Rokkor lenses would be my long time favourites. Both 28mm, 40mm and the 90mm.
But so far I've settled for Voigtländer lenses, which are usually quite nice, but sometimes getting a good specimen can take some effort.

Nevertheless, my current favourites include the 21mm Skopar, even though it's not particularly fast. It's small and nice to use as a walkabout lens, and covers a moderate wideangle view.
On the tele end I use the 3.5/90mm APO-Lanthar. Quite a nice lens, lightweight and sharp enough. Comes with a nice metal lens hood.

Then, even though I recommended against adapters and other mount lenses, I'm still using a 2.0/58mm Helios as my "poor man's cine lens" with a Fotodiox m42 to LM adapter. It's surprisingly good for the price these days, provided that you can find a good specimen, and a manual version with three rings, with the aperture ring and the opening/closing ring at the further end of the lens, and the focusing ring closest to the lens mount. The biggest downside of this lens and adapter combo is the obvious one, the weight, which makes the lens and GXR combo a bit front-heavy. Which is true with most SLR lenses with an adapter.
But anyway, that's my short list for M mount lenses.

[Cleveland guy]

I've recently purchased a Ricoh GXR to use my old LTM lenses, and I think the camera is terrific. It has a few quirks with its menus, but overall, I've been really impressed with the results.

I'd also like to recommend a few bargain lenses to consider: the Russian-made Jupiter 12 35mm f2.8 Biogon copy is a nice, small 50mm-ish lens on the GXR. Mine is sharp, although doesn't focus terribly closely. Secondly, the also Russian-made Orion 15 28mm f6 lens is quite nice in good light, they're a bit rarer, and close in cost to a used 28mm Voigtlander. I also own the Cosina Voigtlanders 15, 21, and 35mm which are all terrific lenses for the money, well-built and great color rendering and sharpness. I use inexpensive Chinese-made L39>LM adapters for them all since focusing in done through the viewfinder.

Lastly, since I wanted a closer focusing wide angle lens, I bought a Canon FL 19mm f3.5 lens and Canon B adapter to Leica screwmount + Leica screw to M adapter. While by contrast to the much smaller lenses mentioned above, it's a huge chunk of glass, but it does render lovely images. Attached are some recent examples, some created using the Toy Camera function in Scene Mode.

Attached Images