At quite a bit more expensive mana and only being able to use it on 1 person vs your like 4-6?
I still wont be using this HoT, ever. It is a waste of mana, heh. It comes from HoT's being ineffective unless you're slumming in low content where you can let your HP fall enough to take full advantage of it and even then you could twinheal and fire 2x 20-25k crits, at a similar mana cost, 1700 x 6 ticks is useless.
In any modern content they are really ineffective at healing, the heal either never heals due to full health, or it only partially heals some minor leftover from the direct heal. With mobs attacking pretty fast and hard, and the need to constantly spam heal it is a lot easier for HoT's to heal for nothing or very little, then it used to be, since the healing time to hit takes too long for modern content.
With HoT's on me tanking and with LoH HoT in raids, I would bet that easily atleast 2/3-3/4 of HoT ticks never heal, for you that may be no problem since you can just Canni your mana back and it's no real loss, since Paladins have no option like this, this makes the waste of mana part pretty big and destroys the value of the spell, if the spell was like 300 mana or heal bumped up to like 6k / tick, maybe it would get some use.
Anyway that's enough rambling. If you want a bigger HoT you could ask for one based on that boost probably. I personally will still never be using this spell ever, nor will I be using the House of Thule version.