I pretty much always commend a healer in the group if they don't neglect their responsibilities altogether (like casting weak DPS spells vs Esuna/Leeches as team members stay slept/bound). It takes a bad healer to not commend, like a healer that leaves me slept for 20s in the beginning to a fully upgraded Nightwing while they cast less important spells.

It's funny you ask this because last night I joined a 24 man Slaughter via Roulette where there were no healers, and so I offered to swap to SCH since no one else wanted to. Respent all my AP's. A WHM joined and I realized during battle they were doing really well and I didn't recognize them so they were prob newer to PvP. I mentioned in the fight even they were one of the better PVP healers I'd seen in awhile after I'd seen how quickly they unslept me each time. We won the game despite the DPS's not getting many nodes pretty much by denying the other teams all but a really small number of kills,we were able to bring people back with PVP res in most cases. Won the game, got 1 commendation, hoped the other healer got the rest... saw they were from my server and spoke with them after to recruit for my LS. Ended up asking how many commendations they got cause I had a suspicion, and I was right, the answer was 1 which was from me. So none of the DPS's we's frantically kept alive so they could play they role they chose thought it was worth the trouble.

So yeah all I can say is screw you Twin Adder ingrates, I've swapped DPS-> Healer for a PUG team in Slaughter for the last time cause this is far from the first match like this. I would rather watch a team die off one by one from now on than take on the hardest job for them, get none of the achievement points related to kills, and wind up with like no commendations for it even if we come in first, what more do you expect from us in a Slaughter match of all things.