I see on the forums slot of hate about this spell. Frankly I've found this spell to be very good however I noticed that nobody that I've read yet has used it like I have. Everyone seems to complain that DPS don't use it and they're very right but frankly I don't want the DPS to use it. Here's what I do for PvE:
Lightwell tank healing:
Allow me to exlain. Lightwell can be used while stunned which increases it's further use. There are alot of fights where the tank stands in one place or moves very little. I place a lightwell behind the tank and during times of stressful damage or mass stunning he'll use it. It's an emergency heal that's right there for the tank to use at his own disrection. You may call me silly but I glyphed lightwell and it's healing for around 5k (after fully buffed) every 2 seconds for 6 seconds. And best of all there are 10 charges for him. This application of lightwell has proven invaluable. And I know some of you maybe be saying it'll be dispelled with enough damage but I have yet to see the tank lose the lightwell renew before the 6 seconds has ended.
PvP healing:
lightwell is amazing here as well mostly because the vast majority of your enemies don't know WTF to do about you healing yourself at the lightwell. You can destroy it but I haven't met an opponent that knew that you can do that.
All in all I love lightwell the way it is. I just thought I'd share my experience with it since it's gone unmentioned. Feel free to comment.