Oh, I kept searching for Garchomp Ban and couldn't find proof anywhere that he was unbanned outside of PS for testing. Thanks for letting me know. Now I can worry about getting Genesect banned to Uber lol.
Anyways, you're team is pretty well rounded. Genesect is a bitch so, boom, there you go. Am I supposed to give criticism to it? It pretty much rounds your team out.
Theirs not a whole lot of weaknesses, however one major flaw I see is the weakness to Sun and Rain teams. Chlorophyll Venusaur has no problems sweeping your team if he gets a Growth up under the sun, and many rain teams couldn't give two shits about your defenses with the right walls and Pokemon. Phazing is also a big issue if your Heatran gets taken out or threatened out, and although your Pokemon are powerful, you have no real hard counters to a Bulky team, who would have no problem setting up hazards and stalling you out. Prediction is all it takes to ruin your team if given the right opportunity (and, ironically, over prediction can ruin yourself). Ironically, other Genesect can ruin you, as they counter your two main Pokemon (Genesect, more irony, and Garchomp) since they commonly run Flamethrower and Ice Beam.
My suggestion would be to run a Tyranitar over Breloom. It has much better Bulk and can even run a SubPunch set (with Fire Blast to counter other Genesect), if that's your thing. It negates your weather weaknesses and even if they save their Ninetales or Politoed, it will not last against a Focus Punch. Of course, their are a bunch of other sets, so I recommend you look at them and choose which one suits you best (also, if you replace Breloom, your team has no weakness to Sandstorm. Not entirely helpful since Garchomp is running Rough Skin, but hey, every bit helps.)
I'm not the greatest at OU however I've been getting better and better after my hiatus, so I hope my advice could help you out (and if not, free bump? :3) Good luck!
"Bitch, I'm a king."