The heal amount is fine. With 3HP, it heals for around 6k per target, whereas WoG heals for about 10k. This means that LoD is better healing per cast when you can heal 2 or more targets, including yourself as a potential target. I wouldn't use it if only me and one other needed healing, as I can hit the target with WoG for more and heal myself via PotI.
Which leads me to this (assume LoD is glyphed, because it should always be in PvE):
If there are 7 players, including you, injured for 5k even, and all of them can be hit with LoD, is it smart enough to NOT heal you if you have PotI?
Also, I did a bit of quick testing to check out both its range and how wide the cone is. The spell effect is much shorter than the spell's actual range, which seems to throw off people. To illustrate this, look at this screen I took:
The view is straight up, the target is straight ahead of me on the An'zu mount (you can see the tail). Left SCT is incoming, right SCT is outgoing. You can see that it is hitting the druid in front of me and myself.
Here's where I would be concerned, though:
Notice that LoD isn't hitting the target on the trike, even though I'm a) closer, so I should be within the 30yd range, and b) the cone looks like it would be hitting him if you extended the rays. From my limited playing around with it, the cone is much narrower than it seems. To illustrate, I tried hitting the player from the first screenshot while even slightly turned to the left and I couldn't hit him from near max range. Only when he was straight ahead is when I could hit him.
Admittedly, I don't have a range finder and this was quick and dirty. I'll try to grab a volunteer from the guild and do some more testing later.
What I get out of this, though: Not too big of a concern when you decide to splash melee with it, but trying to hit ranged that aren't basically in a line is basically asking your LoD to not land.