Terran are my favorite right now
I was looking through the gamespot guide for this game.. The graphics seem very scalable. There's a negligible difference (if any) between Ultra and Extreme shaders. I turn everything as high as they'll go just 'cause I can
I don't see any framerate drop between Ultra and Extreme, so I'm good there.
My old favorite from SC: BW were Protoss > Zerg > Terran, in that order.. Now I think it's Terran > Protoss > Zerg. I used to be a Hydra / Lurker rusher, but since they took out Lurkers (replaced 'em with Roaches), I just don't have that same love for Zerg.. Lurkers were just too awesome
One thing I've learned from this game as opposed to SC:BW: Diversify! In Brood War I used to spam a single unit type early game (Marines, Hydralisks, or Zealots / Dragoons).. Now I go all through the tech tree.. For Terran, it's Marines, Medivacs (which replaced the Medics and Shuttle.. combined them), Reapers, Marauders, Vikings, and Hellions.
I really like the gameplay. I just wish I had more people I know to play with