[Ash]

You will have to decide what you value more - high ISO or more advanced features and customisation, pentaprism and weather sealing.

[Boris]

Body's get replaced, not disposed. You see the number of people here still using
k10/k20 and some of them make nicer pictures than people with k-7/k-5

Right. My daughter uses my old K10D with great success.

Looking at agiotage that hits the forums when new camera comes out, I have to conclude that bodies in fact do get disposed. Unfortunately.

[ewig]

You will have to decide what you value more - high ISO or more advanced features and customisation, pentaprism and weather sealing.

oke ..thanks.. i will reconsidered it... but what about speed AF from both ? don't you think K-r has little bit advantage in low light ?

[weatherproof]

I told myself that my next camera would have weatherproofing because I've been caught in a few rainstorms and didn't want to stop shooting (and hate the plastic bag hacks), so a used K-7 was the best choice. In addition, I knew I would eventually upgrade to a used K-5 in a year or two, so having very similar interfaces would make the transition smooth.

Like what Ash said, you need to think how often you'll be shooting in situations requiring high ISO or weatherproofing and go from there.

As for AF performance, I'm sure both are better than what you're upgrading from. So unless you're shooting sports, I wouldn't stress that too much. You learn to adapt to the gear.

[Frogfish]

The K7 is not a bad camera when it comes to low light ... it's just that many other cameras on the market are better (Kx, Kr, K5 and recent CaNikons amongst others). That doesn't mean you can't take great shots with it in low light !

I am in the same boat as you in a way. I have the K7 now and the K5 will be arriving in a couple of weeks ... however I will need to have 2 bodies this year (for some commercial shoots) and I have been debating whether to sell the K7 (it's actually up for sale where I live now) and get the Kr (for the new sensor and AF) or stick with the K7 for the factors already listed in this thread and for the fact that the K5 & K7 share an almost identical interface (which would make it very easy during a shoot).
This thread actually swings me back towards keeping the K7 because I know it can take some great low light shots - the K7's focus assist & pentaprism facing off against the Kr's better high ISO performance.

And then there is something else which I didn't realise made sooooo much difference until I bought the Tamron 17-50 last weekend, even though I have several very fast lenses. The lense makes a huge difference to the ability of any given camera to focus quickly and efficiently - even in low light.

These were all taken in low light, as you can see, and yet I had almost immediate focus lock for every one of them (K7 & T 17-50).

https://www.pentaxforums.com/forums/post-your-photos/126657-landscape-sunset-...west-lake.html

[eddie1960]

I think it is rather easy. If you can stand the worse viewfinder of K-r, then it is no-brainer - K-r. Otherwise it will have to be K-7. Keep in mind that camera today is pretty much disposable item. In 2 years since now it will be old and in 3 years since now it will be ancient. In 5 years you will be effectively forced to upgrade.

If like you say you use manual glass, then K-7 with viewfinder magnifying eyecap and a split screen focusing screen (prepare to do some shimming) may be the best course of action.

One point though, in low ISO K-7 is not superb. It is ok, but no more than that. Oh yes, I have it, so I happen to know what I am talking about.

The k7 with a split screen is great, i put in a k3 screen (old nikon adapted to size by vendor) and didn't need to use the shim (haven't done a critical focus test yet, but it does seem right on target) it's a joy to use, I use a pentax M+3 eye[piece to offset by my prescription value. at the rate my eyes are deteriorating i figure i have a couple of years before i have to use my glasses with this set up
after the k10 i feel the high iso benefit outweighs the low iso drop (it may not be kx/r or k5 high iso but it's a damn site better than a k10