Results - Back from the Range!
Okay, I'm back. I told you guys I'd just go install one and see what happens.
Here it is. I installed one of the Wilson buffers (blue) correctly and marched off to the range with 200 rounds of the same 230-grain cast RNs I've been using for a couple of years. They're warm but within spec, so they reasonably approximate the recoil impulse of factory or GI ball ammo.
Of 200 rounds, I had 3 failure to feed malfunctions. That's normal for these loads - I have a polished ramp but they still hang up on occasion. I did notice the 'slam' of the slide against the frame that I'd experienced before went away, along with a slight but noticible reduction in recoil. There were no failures of any other kind. The slide remained open after each mag was empty, and it behaved just like you'd expect it, mechanically. I double checked my records and the recoil spring is a Wolff "factory weight" with less than a thousand rounds on it. I could play with a slightly beefier spring for these loads and maybe get a reduction on the slamming effect, but the whole idea on the question as I began was whether the buffs are worth anything at all.
My conclusion - yeah, they work, on mine anyhow, without causing problems, and I know they're supposed to be replaced every 1000 rounds. We'll see how it deteriorates as I continue to shoot it. Since this isn't a CCW piece at all, and gets frequently shot at the range, I'll likely keep the bufs in there until I use up my six pack of 'em, and go from there. I doubt I'll buy more when I've worn them out, but as noted, I had a handful of these to play with, and I'm curious by nature. I'll agree that tinkering like this is asking for trouble on a "combat weapon" of any kind.
So there ya go, guys, just one shooter's observations - and thanks to all of you who took the time to ponder it and offer ideas.