You can find a demo for it on Steam.
I'm a big fan of the original games (Forged Alliance expansion included) and was really disappointed with the major changes they made to SupCom2.
To sum it up, they drastically lowered the complexity of the game (in particular the economic aspects) and made sweeping changes to the appearance and scale of the game.
If you enjoy simpler RTSs with larger units in smaller quantities fighting on small battlefields over resource points, then you'll probably like SupCom2. It is quite comparable to CnC and Starcraft now. Unfortunately, it turned down the scale and complexity negating much of the strategic nature of the first games, but didn't adequately improve the tactical nature of the game. World in Conflict implemented small scale tactics based gameplay with not even a hint of base building and it did fairly well at this.
SupCom2 sacrifices the few traits that made it unique in order to appeal to a more mainstream audience. Brighter colors, chunkier unit design, smaller battlefields, cheesier dialog, and small scale combat are apparently what sells right now.