You can't hate blacksite... but you can't love it either..
The online multiplayer is ok. It's kind of like pc gaming or games like gears of war 1 where there's a bunch of lobbys and you can pick which one you want to join.... problem is so few people actually play online, for example when I was playing a deathmatch game the most people in the game was a mere 5. The online multiplayer can go up to 10 which is still small.. but good luck getting 10 even into your game.
Also sometimes it can take FOREVER for your opponent to kill you or for you to kill someone. I remember that me and this other person was duking it out with our pistols for about 30 seconds. Even with the assault rifle it can still take forever to kill someone.
The graphics are nice enough and your environments will vary a lot so you won't be dissapointed in that.
The good: Solid campaign, easy controls, nice graphics, vehicles are fun to drive, there is online multiplayer
The bad: No local play, no bots, no running, people hardly even play on xbox live
Conclusion? On amazon you can get the game for under $15 new and under $15 used O.O as of now new and used prices are about the same.. It's worth a buy at that price I suppose.. I mean I guess it is worth $15