Unlike any RTS you've played, which turns out to be a very, very good thing.
Graphics: On a high-end computer, even this will have to be turned down in the large scale. If you have a Quad-Core processor, then this won't be as much of a problem. It looks great if you can handle it, but it still looks good at low levels.
Sound: Jeremy Soule composes the most amazing soundtrack I've ever heard (He did Oblivion, Morrowind, Guild Wars, Warhammer: Mark of Chaos, Company of Heroes, and Prey, in case you haven't heard of him). The unit sounds are all unique, so you will usually be able to identify who's shooting at who just by listening.
Value: With 3 campaigns with 6 "Operations" (each one being at least an hour, not including the first one), there is plenty to do. Also, having 3 different factions for skirmish and multiplayer lets you learn how to use each one. The differences are subtle in most cases, but you will notice them.
Tilt: A great game, probably one of the best RTSs I've played, but I don't want it's score to be up there with Oblivion and Twilight Princess.
Overall: 9.6. If you are looking for something new, buy it. If you want a good RTS, buy it. If you want a great game, buy it.