Going back to the original topic....
I LOVE alacrity! It's one of my favorite stats. Especialy since if the spell is less that 1.5sec it also reduces the GDC.
This helps out alot on your HoT->channel->life tap combo. And since using this can give you unlimited mana, that gives you the ability to really use the bonus our HoT gives us for other things, quick Dark Infusions, cheap AOE's, ect.
I've played with both and using lots of alacrity really makes us more nimble in a lot of situations.