Definitely Stevens. Smart is coaching a bunch of players he didn't recruit, and has been stated, VCU foundered big-time down the stretch and honestly shouldn't have been in this tournament at all. Moreover, I've gotten the sense in watching VCU in the tournament that it's not that they're doing more with less, really; they're doing a lot with a lot. VCU has some pretty damn good high-major talent on that team, such as our boy Skeen. Butler plays ugly and wins ugly with more "typical" mid-major players, making their successive tournament runs a little more impressive to me.
On the other hand, taking Butler--BUTLER, for chrissakes--to back to back Final 4s is fucking incredible. The fact that Stevens has done it twice takes a ton of the flukiness out of it for me.
Don't get me wrong, Smart has impressed the hell out of me with his motivational tactics, changing defenses, and his ability to inspire confidence in his guys and keep their energy high (something we could sure use). I just think Stevens's accomplishments to date have been more impressive.