I used standard low-brass bulk-pack trap loads, both of them cycled perfectly, and both booted my shoulder pretty hard - I've been spoiled by the R3 pad on the 870. (Not to mention the weight of a 3.5"-receiver pumpgun.) The 37 slamfires just like it's supposed to, and the trigger is still heavy. I'll swing it by Diamond Gunsmith one of these days to see if Les can clean it up some. The 1100 is a dream - swings smooth, trigger breaks clean, and cycles perfectly - and I only tried to pump the gun once. I expect I'll invest in a lace-on leather recoil pad for both guns as well.
Once the long guns were put up, I ran a few magazines through the M&P9, and it functioned perfectly. Unfortunately, the LaserLyte RSL didn't do so well. The spring in the switch is apparently weak enough that recoil from a 9mm will change modes (from off to on, steady to pulse, and pulse back to off), and the set screw doesn't hold the sight in place - I wondered why my group was walking left until I changed mags and noticed the whole assembly had shift a few 16ths of an inch left.
Burned through the carry ammo I'd had in the Kahr since last fall, and headed home, gunpowder-lust sated for a while.