quickness stacking
 

Does heroic quickness stack with quicken self spell by number of attacks?

Yes it does, I've seen quickened commander with heroic quickness performing 3 attacks per combat turn.

Re: quickness stacking
 

I once had a Sea King with personnal quickness and a high heroic quickness doing 4 or 5 attacks per turn.

It was a pain to get him enough reinvigoration ... ^_^