Took my T/C Contender in .45-70 to Magnaport Intl. after realizing I'd never shoot it again unported. I think my hand was still numb at the time. No, it's not a carry gun, but it did have the full rifle style porting done. Took them about an hour while the wife and I had lunch in town. A good experience all-around, the porting worked pretty much as advertised, though the gun is still truly a handgrenade-full.
I have never done this, but I don't see the benefit in a 9, 40 or 45. Maybe in a 44 magnum...
You'll see far more benefit from 9mm or .40 than .45.