I'm playing it right now!
The first couple of levels are pretty bad...(tight corridor sections, maze-like design) but it picks up right after that and becomes awesome (open ground, tons of enemies charging you).
Playing on serious difficulty and sometimes you hit a choke point and it's like whaaaaaa who designed this POS.
Really fast paced, tons of enemies on screen, and really fun. I haven't started Saints Row 3 because of this!