I use 'em, and they come up in the big fights on occasion, and in the little fights pretty regularly -- someone moving by someone else, that kind of thing.
Only change I've made with respect to pistol whips is that you can, once per round as a free action, declare whether your gun is being used to line up a shot, or to prepare for a pistol-whip attack. If it's being used to line up a shot, you aren't treated as being armed in terms of pistol-whip attacks, so you don't get to take an AoO if somebody runs past you.
As it works out, it doesn't completely eliminate them, but it does cut down on them. For example:
Round 1:
Move to draw gun (defaults to shooting style)
Attack to shoot gun
Free action to have gun in pistol-whipping position
If somebody runs by him now, he can pistol-whip them.
Round 2:
Free action to switch to ready-to-shoot mode
Move to grab some cover
Attack to shoot gun
If somebody runs by him now, he can't pistol whip them, since he's in shooting mode
Round 3:
Attack to shoot gun
Free action to have gun in pistol-whipping position
If somebody runs by him now, he can pistol-whip them.
And most of the time, my players, who are more roleplayers than minmaxers, will just say "I'm not switching to pistol-whip mode. I'm shooting stuff, and that's that."