About the THF chain...

[knightgf]

I still cannot fathom how EXACTLY this works as a feat...can someone help me explain it better and if its really helpful to take as a barbarian? From what I understand, this feat increases both the chance and the damage that glancing blows do by a certain percentage per feat, thus helping my base damage in a way. Considering that the FrB prestiege does increase the chance for glancing blows as well, would it be worth taking the THF chain as well, or would these 3 feats be better spent with something else?

[Kinerd]

THF feats affect (and effect) glancing blows. All the information you need numerically is here.

Outside of twitching, you get a pretty hefty increase by getting all the THF feats. How much specifically depends on your gear set-up, but roughly speaking it's as or more important than Power Attack by end-game. If you want to do exceptional DPS, nothing else compares. You could instead decide to twitch all the time and therefore not get any THF feats, but this would leave you pretty far behind against certain targets.

If you don't care as much about DPS as some other goal, then it's harder to say if you have better choices for your very limited feat slots.