I personally prefer holy's playstyle but I feel disc is stronger for 10m on most fights. I personally run disc/holy and swap on a fight to fight basis but honestly, I mainly use disc for progression and only use holy on farm bosses. My guild is 5/13H atm and the only boss I actually feel holy is stronger on is Heroic Tortos. By the nature of having 2 choices, one is going to be stronger for each fight; it's just how far apart disc and holy are for a given fight. Some they will be very close together and others, one will pull way ahead. As it is, on most ToT fights disc is ahead of holy by a decent margin.