Make G-THF better, it deserves to be better. Either put the glancing blow back on the first swing while moving so that people will see glances on the 90% of content that doesn't stand perfectly still- or add damage to the feat in some other form.
That is all.
Oh wait, no that's not all...... Also, fix Great Weapon Aptitude. None of the ranks do anything at all and its not listed as a known problem. Many players are not aware that this enhancement is 100% broken, and thus waste 6 points on it.