Finally got around to revising my GBU Singles team. I replaced Bisharp with specially defensive Tyranitar, and am now using an offensive TR Reuniclus instead of a bulky CM set.
I've been using this team in GBU Free mode for a little bit, and I'm getting about a 60-65% win percentage (not counting ragequits.) This weekend, I hope to try my footing in Rated matchup. I'll update later about any success there.
What I like about my new lineup is that I can run several different strategies. Scizor and Rotom-W form an excellent VoltTurn duo. Reuniclus and Tyranitar are both terrifying to face under Trick Room, not to mention Scizor. In a pinch, Scizor can tank physical hits and form a defensive core with Tyranitar. I'm honestly considering going full-out Trick Room and replacing Froslass with Ferrothorn, but I'm not sure I'm quite willing to give up the former's utility.