Is GW getting insanely difficult for any other lvl 80-85s?

I've played the game pretty much since release but since I'm 100% F2P and took a break for a few months I'm somewhat behind in roster development and whatnot compared to others in my shard. I used to never be able to get past node 6 in GW before nihilus came out. I've used him as my lead ever since and haven't lost a single GW battle. And all the characters I ever use are nihilus, vader, palp, sid, dooku and STH and Rex (STH against node 12, Rex against zaul teams)