Wow, this game is very entertaining! I'm not sure about solo... I soloed it up to the blond chick before restarting with a friend and the coop playthrough was a much improved experience. I may reserve this one to coop only. I was Sheva for the coop, though, and I think I prefer her side to Chris'
The inventory caught me off guard, though. I kept reading that it was 'optimised' for PC, but other than mouse use how is it? Looking at its setup I figured I could easily use the numpad for the buttons that correspond, but I guess I still have to remap each one?