Out of all the semi-auto pistols I've owned, save the 1911, the P99 with the smallest backstrap was the one that felt the best and was the most recent. The trouble is that the backstrap does not change the size of the frame directly below the slide, like I stated previously. It wouldn't get bloody like the M&P did, but it was still fairly uncomfortable to shoot for extended periods. I couldn't get used to the "hump" at the bottom of the grip, even with the small backstrap. I like a flat backstrap, like a flat MSP on a 1911. I understand the SR9 has the reversible backstrap that allows for an arched or flat profile, and the one I handled had the arched installed and was still VERY comfortable.
Still looking for opinions, but I have it narrowed down to:
SR9
BHP
Kahr
3900 series
The only thing keeping me from taking the plunge on the SR9 right away and coming here to seek other potential options was the trigger (HEAVY!) and lack of a reputation. The trigger is something I could get used to through practice, so it isn't that big of a dealbreaker.