I'm planning on getting a P229 in 357, but my P228 9mm will most likely remain my carry gun. The P229 will be nice to carry in the woods though. I've been near an angry adolescent black bear once, and at that point I really wished that I'd had something a bit more potent than 9mm. Cost not an issue, I'd get the 357 every time. It's like 9mm on meth and roids
9mm guns I've shot: P228, P239, P225, G17, G19, 92FS
40 guns I've shot: SP2022, G22, G27, USP40
357 guns I've shot: P226, P229, P239.
I'm pretty much immune to pistol recoil, but my perception is that the 357 kicks just slightly less than the 40's, and the 9's have very little recoil at all.
If self defense from people is your concern, a higher capacity 9mm loaded with Speer Gold Dots is damn hard to beat. But 357 definetly wins out on power, penetration, and accuracy at longer ranges. And its COOL.