I saw a Krav Maga class once, I was not impressed. They didn't do any groundwork, which is critical for self defense whether you want to admit it or not. It was more like a "Cardio Kickboxing" class, and everyone there had their official Krav Maga Tshirts and duffel bags
just another marketing gimmick, IMO.
I rolled with a Krav Maga guy once and he had no idea what to do. Sure, he could have starting biting me or whatever crazy **** they teach you in those classes, but I could have done the same to him, and I had the dominant position the whole time, so I probably would have won that one.
We had a thread on the effectiveness of BJJ for self defense and many people including myself pointed out that BJJ is not just about staying on the ground. It also contains sweeps, reversals and escapes to get back to your feet.