I think if they were to give WHM the same treatment as AST (usable new abilities, a mechanic that worked for healers) as it stands now WHM would be the only choice for healers. I've only done the first new dungeon (I'm progressing with someone and he's had a ton of work lately) but I've also done a bunch of older content which I also did as HW WHM and the potency increases are real. Even without the 10% CS buff I pulled off of tanks while DPSing fairly regularly and the heal potency let me do more damage because my heals per GCD were bringing him back up that much more.

I pretty much ignored lillies but that was okay. I'm all for redoing lily and confession systems but then I think WHM will need a potency nerf or it will just be too OP.