Before I even start - I know the answer to my question is "only you can know the answer"... but I know the fine folks in this forum can think of things from a point of view that I might not be seeing. So I'll explain what I'm trying to decide...
I'm about to ship some lenses once I get out of the house (long story, I'm not sick but was a bit sick last week so I'm basically quarantine-ing myself).
So I am in a position to soon be able to spend a couple hundred dollars and changeon a new lens... and I keep telling myself that my next lens has to be the DA 21 Limited - it's easy to find it under 200 dollars these days (SMC), or the HD version can be sometimes found used in the mid-200 dollars.
That's what I thought a couple of months ago too, when I also sold some things and had some cash... and a DA 35 Limited appeared in great condition for 179 dollars shipped and I jumped on the "best lens ever" instead of the DA 21
I don't know if I'd use the 21 that much. While I think that carrying the small wide pancake on the K-S1 would be the ultimate little street and walkaround setup, the fact is that my DA 16-45mm does such a great job, and f/4 is not that different from f/3.2. The 16-45 certainly does not lack sharpness with my 20MP sensor, even wide open (though contrast, microcontrast and color saturation improve as you stop down - they're not bad to start with).
I think I'll like the DA 21 this time around... I had it for about a couple weeks some 5 years ago but that trade ended up reversed... and I missed the DA 16-45 that I had traded for it (plus cash). This time I'm keeping the 16-45...
...but I just love the pictures of the DA 70. So am I going to end up with that instead? I don't really need the 70 either, my 50/55mm lenses are probably close enough, and my M 100 2.8 takes gorgeous pictures. Either lens would be a treat.
So considering I have...
DA 16-45
Tokina 24 2.8 (which I do like but the DA 21 would definitely be an improvement)
M 28 3.5
Sigma 30 1.4
DA 35 Limited and 35 2.4
several 50s including K 50 1.2 and K 55 f2
M 100 2.8
Takumar Bayonet 135 2.8
M 200 f4
SMC-A 70-210mm f4
Tamron 70-300 f4-5.6 LD DI
...among others, what would you do?