I think the problem is a lot of the reviews were done when it was full of bugs. The game is all right though, it's not the best game ever. However ID have always been more about show casing their engines in games rather than making the best story driven game around. It's still an enjoyable shooter though.
It's fast paced and the way the aiming responds just feels really nice.
Personally I would have preferred they not bother with Rage and just concentrate on giving us Doom 4. They have said that doom 4 will be better on the PC though, so maybe they will put a bit more development into what is a classic PC title. Rather than the consoles this time.