What are you guys going to do with your Fighters at levels 15+? Do you really need 3 more fighter feats at L16, 18, 20? Or could you benefit more from multiclass feats/enhancements?
I suppose it really depends on what new high level feats/enhancements they introduce. But, I'm having trouble seeing many reasons to stay pure Fighter. Personally, Barb and Bard are out because I'm LG. But, Ranger or Paladin are viable options.