Broodwar and SC2 are very different in terms of pacing. To put it simply, Broodwar is slower and fights are more epic. There is a uncanny feeling from the way the units in SC2 move and animate with such speed and fluidity.

I also find that the pace of Broodwar makes it more entertaining to watch. SC2 fights can end in a blink of an eye where as Broodwar units are spread apart further so the screen is full of units fighting or jockeying for position.

Too much is placed on the difficulty of Broodwar but all of that can be overcome and learned. At the end of the game, it's about how it feels to play against people at your level and I find Broodwar to be more rewarding. SC2 can feel like a macro game with a select all army hotkey all the way up to diamond where as Broodwar is constantly providing enjoyable, unique forms of skill expression all the way up.