Equipment burden needs to be under 50% for full speed roll. I'm not even sure it's possible with stone armor (or any of the really heavy stuff) unless you double up havel's ring and wood grain ring. (Even at 99 end, equip burden is surprisingly low.)
ahh, thanks. one more thing: i've got several "unique" boss souls now and haven't yet found an opportunity to use any of them to make special weapons and whatnot.. without spoiling anything..am i missing something, or will it be blatantly apparent when the time comes to use them?