I'll definetely try the demo before buying. But my gut feeling is that 7/10's my be a bit high for this game. The main rave point for this game is the destroyable environments and buildings. The story line doesn't really grab me but a really mediocre single player game can be buyable if the multiplayer offers something unique and fun. However awesome it may be, when you deal with a lot of physics and destructible environments you're going to have l...a....g..... Which tells me that online play may consist of pretty small maps to try and help counter this.
Not 100% either way on this one. Demo's can be misleading. I'll reserve final judgement after the release.