Enjoyable gem that had the misfortune of releasing amid two blockbuster RTS titles, thus lost in the shuffle...
The AI is very competent and downright brutal (without cheating) at the hard setting, which is a refreshing experience.
To me the game strikes a great balance between being fast-paced tactical and strategic. The multi-player mode is my favorite, but even the two campaigns are fun and largely challenging.
If you enjoyed Act of War, C&G: Generals or similar titles, this is a great title that many unfortunately missed because the release date was sandwiched between blockbuster RTS giants like Supreme Commander and Command & Conquer 3.
Still, if you are looking for a well designed fun RTS that doesn't require a top of the line rig to play and still looks good and features a solid and challenging AI that may often surprise you, I'd look for War Front. After all, it had nukes before World in Conflict, Sonic Tanks before the new C&C expansion, and many other innovations that others have since "borrowed". And the price is right as well.