Gears of War PC vs 360

I just picked up Gears of War for PC for dirt cheap.  It's interesting that I have the settings maxed out and it is stressing my system.  Most of the time it runs smoothly but there are some framerate issues.  Also there are loading times.  WTF!  For example, remember in the first act after you fight off the 4 emergence holes from the round fountain you have to plit up into two groups?  I tool the right side like I normally do.  As I ran up the hill to the hallway right before I rounded the corner to shoot the locust on the troika I had a loading screen.  How does co-op work with this!  Tank or Zorbs, we need to do this.

I haven't played a fresh Gears since the first time I played it on the 360.  But on the PC version Act I and Act V are available.  Why is Act V available?  Is that where the Brumack battle is?

I am using my 360 controller with this game.  Since this is a slow paced game it really doesn't benefit much from mouse aiming.

I didn't look at a multiplayer yet because I just don't care.  I think Gears is one of the worse multiplayer games made.