There's a House thread for Klingons in Qo'nos section. Klingon faction has definately picked up since Season 2 so Dstahl & co are defo doing something right. There are many "pure" and good House fleets Klink side, but I won't name them here at a risk of leaving someone out. Persoanlly, I'm a part of Mogh Dynasty and we currently have enough members playing daily to do STFs, (That said Klingon ground play is broken imo) ^^ Group PvP, in-house C&H etc etc. I can't claim that everyone is "pure" Klingon but nor would I expect so seeing federation is a big part of STO but there are quite a few who don't play much Federation if at all.