I'm familiar with and decently competent with revolvers, 1911s, striker-fired, and DA/SA pistols, usually carry a polymer-framed DA/SA pistol, and
I'm the one who needs to step out of my circle? Got it.
The last class I took (about a month and a half ago) I used my S&W M10. I had no problem keeping up with the autoloaders and I was the first revolver shooter to pass that class. If you know how to run a round gun it's not that big a deal, though it does take more work on the shooter's part. My guess is that trainers who structure their classes around high capacity autoloaders do so because a) they know that's what most of their potential customers have and b) they themselves don't know the revolver well enough to train other people on them.
Capacity - mo' ammo is mo' betta' unless you're swimming or on fire. That's the only reason I switched to carrying a bottomfeeder. My concern here is thinking that because you have a lot of ammo that you can piss some of it away in a defensive shooting. You're legally responsible for every round you fire and hitting an innocent person instead of a bad guy will suck for both of you. I hope that the discipline I've developed in years of revolver shooting is still there if I ever have to use a gun to defend myself, regardless of which gun it is.
I agree, and that's why you see them in most cops' holsters. LEOs have limited training time and most of them aren't shooters to the extent that folks on this forum are. If you're willing to put the time in, though, it opens up a lot of options.
Right now you're in the "you don't know what you don't know" mode concerning revolvers. If you've got a friend who owns a decent (S&W, Colt, Ruger) 4" revolver, see if you can borrow it some time (though sourcing ammo for it right now might be a problem) and put a couple of boxes through it. You might like it, you might not, but at least you'll have that experience.