I didn't like Supp Comm 2 for the simple fact that it was too much flash not enough depth, a unit with 16 horns and 14 toes didn't make it any different or have anymore personality than the next. I honestly don't think Supp Comm2's graphics are superior to SC2's, they are vastly different styles of artistry and SC2 looks pretty damn good on ultra settings without suffering from massive frame loss, unlike supp comm.
SC2 may have less units, but they all serve a purpose. There is not one unit in SC2 that is useless, which I'm positive can't be said for supp comm. SC2 isn't a game where you tech up and tier 1 units become obsolete, tier 1 units are just as important early game as they are late game. It's a game engineered more for competitive gamers than for casual gamers. Of course there is always the campaign, which was extremely good.