I'm a huge Supreme Commander fan but Supreme Commander 2 is a poor imitation of the original.
Power plants used to boost production on factories and the like now make no difference how you place the plants. The water maps where almost totally removed from skirmish games and one race doesn't even have any water based unites making an entire tech tree worthless. The experimentals are no longer as menacingly powerful as they where and the lack of verity of units is disappointing. I miss having tech 1-3 and fingering out when is best to upgrade and move along. The tech system they use now is a little bit like Demigod and is totally inappropriate for a game like this. Also the fact that all the maps are much much smaller is also bothersome.
Some features I used all the time like the move in formation option is removed from the game. I can list a dozen more things that are removed but I'm getting to upset to keep commenting without saying something offensive. I'll just say there isn't anything new that is better then the original and much was taken out and boiled down to seemingly appeal to the console crowds. If you like the first Supreme Commander DO NOT buy this game.
The only redeeming hope for this game is a kick ass mod that will probably never be made because this game looks like it would be a pain in the ass to try and mod.