At first i was kinda disappointed and had some mixed feelings but after few hours of playing i know its Masterpiece.
Everything works just as it should. As COH player i wasnt sure how can game that i was playing 12 years ago can be better than COH without some advanced physics, destruction engine, vehicle wrecks etc. but now i see that all this fancy things was not the problem for Blizzard to do but they didn't cos they didn't want SC2 to loose its main focus - gameplay. Once you start playing MP a new world will open for you. There is no 2 similar units, every unit you have in SC2 is there for a reason. Number of strategies you can use in SC2 is just mind-numbing.... All i have to say is - try it for yourself and make decision about this game after 10+ hours of playing ;)