Zardnaar
Legend
If you eliminate the -5/+10 part of GWM you should also change the name of the feat as now the feat is just as good with any melee weapon.
Maybe call it Melee Weapon Master or Cleave or something.
Cleave would work but I would not have the feat work with light and finesse weapons. The good melee feats are strength based I think because dex is so good. With GWM they over compensated IMHO.