I'm going to have to agree, just because something looks similar doesn't mean it's the same quality. I know that OBX LSDs work just fine for street cars (but what does making 600 HP have to do with how well an LSD actually does it's job??).

There's a lot more to what an LSD does than just not breaking. I'm sure if all you care about is drag racing or normal street driving, the OBX unit is perfectly fine and a good deal for the money. If you actually want a decent LSD, you buy a decent LSD. A non-adjustable LSD is pretty much worthless if you're actually using the LSD for something involving cornering, unless you're not pushing the car hard enough to make a difference. So yes, if you don't need the performance of a Quaife, etc., an OBX unit is fine. For a street car, I'd take the OBX and save money; you really shouldn't be hammering the corners that hard on public streets. Who cares about a straight line, any paperweight LSD would work fine for that simple job.