I own a YUGA and IMHO, they SUCK!!! They are fast, but can't cut corners that well and rarely DOESN'T lock up... i.e. They lock up on almost every alternate turn for me, but then again, maybe that's just a problem with my turning style...
I have one of those exact cubes(same vendor etc) I bought it in jan. and I love it, it does lock up but not that often, and mine cuts corners very well, and never once have I had it pop on me.