I'm not familiar with the knowledge devotion thing that is being refered to though. Could someone give some more info on it?
Well Knowledge Devotion is a feat that rewards knowledge checks with a bonus towards attack & damage.
But the real prize is the Knowledge Domain Affiliation in Complete Champion (the same book where Knowledge Devotion is found). It is a group in which through different things you can raise your 'rank' in the group and thus gain higher benefits.
Student (Affiliation score of 4-12): gain a +2 bonus to one knowledge skill.
Academic (Affiliation score of 13-19): once per day gain a +2 to an attack, save or check.
Master Research (Affiliation score of 20-29): effective caster level for divination goes up by 1.
Scholar (Affiliation score of 30 or higher): Once per day, negate a single ability of an enemy creature that you've discovered using a successful Knowledge check. The effect lasts 1 minute and is a supernatural ability. The creature can attempt a fortitude save (DC + your character level + your int modifier) to negate the effect.
You can raise your affiliation score through things like character level, knowledge ranks, winning a battle through identifying a monster's abilities via a knowledge check, recovers lost pieces of knowledge, ect...
Basically, this is a game changer as you can potentially negate a spell-caster's casting for up to a minute through a knowledge check (which I really think plays to the whole "uses up to 90% of his brain.")