Viddler

I think the greatest achievement present is the fact that most of the drops seem to happen during the background loading. For example, when transitioning from cut-scene to gameplay, and moving from the destroyed bridge to the area with the flood gate. The most obvious occurrence is on the elevator.

The frame-rate remains almost completely solid during the actual gunplay. I'm surprised just how well it was maintained even with all the explosions in the ware house. I would expect the particles / physics to cause some drops, especially near the props that can be deformed or broken into pieces.