Form, feel, function.
To me, the SR9c blows the other options I had (Glock 26, XD, M&P) out of the water in terms of feel. It just fits. Plain and simple. WIth the 17 rd mag I haven't fount a CCW that has a more balanced feel.
The function also sold me. I did a little research. Apparently Ruger took ideas from the best CCWs out there (again, Glock, M&P, XD) and integrated some of those into this pistol. IMO they wanted to take all the positives of the others and make one pistol that incorporates them all. With the different options in mags, adjustable sights, easy to use slide release and safety, and the great trigger pull from the factory it was a no brainer. That and I got a killer deal from Gun Envy at a show.