Priest Healer for 2box

So I have been dual-boxing Priest/Lock for several years now and the new Disc talents seem to push it to be more aimed for single target healing with bubbles while Holy is pushing group heals. I plan on only 2boxing my DK/priest and my Lock/priest and so only have 2-3 targets (pets included) to heal. What do you think of the new Disc talents in comparison with holy for 2boxing? Deep holy seems to be heavy raid spec but I like the larger heals and mana efficiency. What are you priest boxers going to spec in the xpac, assuming the current talents remain similar?

My priest is holy and if you are dual boxing a lock I would go holy for the increased mana regeneration etc and less work needs to be done for your priest which means you can heal ur lock more which means you can life tap for more mana etc.