Not even switching off Penance now - with 4 set bonus cast offensively on the move it is simply amazing and only no-movement boss Garajal is currently outgeared (not to mention mana did not matter here even during progress)
I'm ashamed to say that I am completely addicted to Glyph of Penance now. I'd suffer major withdrawal symptoms if someone took it away from me. We love each other and we're getting married soon. I never swap it out.
I can see the argument of PWS glyph and crit - however, don't think our crit rating is that amazing atm, plus, a lot of times I shield a tank on ful hp. The PoM surely misses a jump, but the last jump ends so often on some pet that... All in all, I think both of them are highly situational and I prefer the bigger tick of PoM on the tank.
I feel disc lacking mobility, and I'm tempted to start using the penance glyph, bit annoyed by the prospect of changing a bind I grew very used to, a bind that doesnt go well with movement (ctrl+left click on vuhdo). Still, that gauntlet on bladelord last night made me so wish I had another heal on the move.
I'm not that sure about the smite glyph, I use atonement in low dmg phases mostly, and it goes a lot into overhealing, so a change to penance might go to that, especially considering the switch on high movement fights (where smite wouldnt be cast a lot either).