Look, OU is broken. It is broken and it will be until it's fixed. Garchomp was a step backwards, in my opinion. The problem, ironically, with Dragon/Ice is that the typical Dragon counter, Ice, is neutral, and you sure as hell aren't going to do much with a neutral HP. This only makes stall harder, honestly. The problem with Kyurem isn't just its offenses, which can be countered by only few Pokemon already, but its decent bulk. 125/100/90 defenses aren't that bad, and make it so it can't be KO'd as easily. Of course, CBand Bullet Punch Scizor and Guts Adamant Conkeldurr can 2HKO it, so it might not be as much of a threat as we thought. Just keep in mind that not much else will be able to be able to KO it. Bulky Metagross, of all things, can counter it: And hit back fairly hard: So we finally found a niche for Metagross. Welcome back to decency, old friend. TL;DR: It's a mixed bag. There are reasons for and against it, I'm just trying to give my opinion.