You know what I figured? I don't like two-player co-op with strangers.
I've like playing with a stranger exactly once. I'm starting to not care about achievements, so once I get into the higher difficulty settings I'll see if the A.I. Sheva is smart enough to handle tough situations. She usually is.
It tended to be better playing Gears of War 1 and 2 with strangers, maybe it was something about Xbox Live players that makes for less tense situations than with PC players. I'll stick with Left 4 Dead now and other 4-player co-op games or Street Fighter 4. That feels more natural, much more like coin-op multiplayer.
As for the game itself? It feels way too much like Gears of War. When I first played Gears, I thought it felt like RE4, just Locusts instead of Zombies. Now RE5 flipped that around, except now, you can't walk and shoot. The cover system also felt like it sucked in comparison to Gears. Also, it wasn't scary at all, nothing all that creepy and the tension was really killed by the co-op aspect, the auto-saving, and the high paced action feel. Alot of enemies come at you, you kill them. You very rarely need to make good use to the wide environments. You just hold up one place and have a shoot out. If they wanted to make it like Gears they should have went all the way, not try to pretend it was still trying to be survival horror. It was simular to how RE3 was different from RE1 and 2, 3 was way faster, more action packed and aside from Nemesis, less tense.
So, why the 9.0 rating? It's way better than Halo and yes, I rate Gears of War higher as well. No way did Halo ever achieve a 10 if Gears of War 1 isn't a 10. RE5 flaws don't make it a bad game, just not what RE fans expected after RE4. This is more along the lines of what I would have expected after RE3, Code Veronica, and definitely after the movies (which were cool by the way).