So i was just wondering, I'm playing this game with my character basicly being a brute who can't speak properly, i've noticed this pretty severly hinders my characters ability to draw conclusions, so i might miss out on the occasional dialogue that might have made it simpler for me.

However i'm giving him some pretty serious skills in charisma/persuasion so i'm just wondering if he's too dumb to benefit from this?

Charisma is not necessarily a waste, as it will allow you to recruit more NPC companions, even if you have low Intelligence. Persuasion might not be very useful since your character will miss out on many conversation options due to low Intelligence. I haven't played a low Intelligence character myself, though... anyone know for sure?

Even with high intelligence and the 'dumb' speech, persuasion seems to be an awesome waste. Apparantly it's not so much the intelligence, but a certain degree of eloquence is needed.