A Counter/Hyper beam Usaring ranks as the 11th best when attacking into Blissey, which is really, really good. Of your list, only the Counter/DP Machamp does better, and it ties with the Confusion/Solar Exeggutor (provided they are the same level)
It's an excellent general attacker nontheless. I'd power it up. Heck I'd power it up if I had 200k dust, never mind 1.5 million.
http://pogomoves.com/rankings/gym-offense.php?defender=242