I've healed with it as a Holy Paladin, Disc/Holy Priest, and Resto Druid. I just came back after a 3yr break and can't wait to heal some more. The best part is I finally got HealBot to look the way I want it to so I love it even more. Would be nice if there were adjustable icon borders to complete everything, but that's just personal preference.
I've tried Grid w/ Clique in the past, not a fan of it. Especially because of the binding restrictions because I prefer using mostly my mouse to play. I tried Vuhdo recently and I HATED the way icon positions weren't adjustable. It made me really appreciate the way debuffs/buffs were displayed. Also, Vuhdo didn't have the option to enable/disable bars below a certain health threshold.
I love your creation, Strife. I will actually be so sad if you ever quit (as we all will at some point). Keep up the hard work, and thanks for your commitment!
Here's a glimpse of my UI after I finished adjusting HealBot and the rest of my AddOns