9mm is great. Effective, cheaper, less recoil, more rounds in the gun. With the state of modern handgun ammunition it could be the best all-around caliber for defense and concealed carry, at least for 2-legged assailants.
If I do decided to go that way I've been considering the Ruger SR9C, are those any good?
I've never heard anyone say it's a BAD gun, but FWIW I've also never heard of a respected instructor or other industry professional give it their nod of approval either. And I think the gun is cluttered with unnecessary "safety" crap which IMHO just gives the gun more chances to fail, though I haven't heard of it happening. For my money I would get a glock or M&P over most anything on the market.