I'd like to share my current team I use at the GBU as well.
EVs: 4 HP / 252 Att / 252 Spe
Hi Jump Kick
Mienshao is my preferred lead, as it can break sashes with fake out,
scout with u-turn and hit really hard with kick and edge.
Regenerator helps with the LO-damage and does well in conjuction
with U-Turn switches.
Trait: Clear Body
EVs: 252 HP / 252 Att / 4 Def
CBGross is powerful force, with lots of attack, a stabbed prio move and good
coverage. It can switch easily into most moves aimed at mienshao and get
away relatively unharmed.
Trait: Flash Fire
EVs: 4 Hp / 252 SpA / 252 Spe
I found sub + 3 attacking moves pretty useful in the GBU, Chandelure often
forces a switch and can safely put a sub up and wreck havoc from behind.