1) Hobbywing certainly isn't crap.
2) Although the specs of the Nano-tech look better than the Gens Ace, I'm a bit wary about ordering an unproven battery from China with basically no warranty. I took the risk with my first LiPo (Flightmax) because the price was right and everything worked out fine, but I'm not sure I want to take that risk again. The nano-tech has no reviews, but the Gens Ace has plenty and they're all positive. Besides, the Gens Ace outputs 120A constant, which is double the ESC, and 240A burst, so I don't think I'll have any issues anyway.