I think the game is alright. It plays mostly like Resident Evil 4.
The pc port for RE5 is a billion times better than the one for RE 4, though. You can easily make it look better than either console version.
Honestly, if you are going to own a version of Resident Evil 5, I think the pc version is the best one to get as long as you have a machine that can run it.
Also, the mouse and keyboard controls are very very good, but if for any reason you don't care for them the game has full Xbox 360 controller support, and allows you the switch between the two control styles on the fly. To switch to mouse and keyboard, pres a button on the keyboard, and to switch to the controller press a button on the controller. That's it. I honestly wish more pc ports were this well constructed.
I know there's a benchmark utility that you can download for free to see if you system runs the game well enough. However I'm not sure if there's a playable demo. I do reccomend you give the game a try yourself instead of listening to the opinions of the haters on this board.
Yes, RE5 was disappointing in comparison to RE4. That does not in any way mean that RE5 is a bad game.