Did LFR on PTR a few times. Might be because of gear scaling, but OMG Disc was soooo much better than Holy... Holy, was struggling to maintain #2 spot (#1 was a Disc), went Disc, easily number one with mana to spare... Now, obv the 480 ilvl didn't help, nor did half my addons not working (both more critical for Holy than Disc), but attonement is incredibly strong right now on PTR.