The 10mm is a fantastic round - actually my preferred self defense round although I am NOT a caliber-nazi! - they all work! I have many of the 10mm's -one of my favorite being a Dan Wesson Patriot Commander and I find it no problem to shoot. In fact, proving that caliber, gun, and configuration all have an effect on felt recoil, on any given day I could easily shoot 500 rounds through any of my 10's as opposed to anywhere near that much through my R9!
A couple of possible problems with porting in a defense gun are increased muzzle flash, blast, noise and the possibiity of a close quarters 'blow-torch' problem - the flash through the ports can be very dangerous - burning a hole through skin, eyes, etc.
I just acquired a Springfield Omega 6" ported longslide in 10mm that I haven't yet shot - I'm interested myself how much the porting and longer slide affect the recoil- I'll post a range report here when I get a chance to shoot it - more Double taps are on their way!