I do not recall our paladin (my 2k+ 5v5 team) ever really using HoJ except on healers when other CC was already done. It is used A LOT in 2v2 though.

I would have to agree, running into the fray trying to HoJ a healer is bit of a risk, however if you are not the focus target then they will probably ignore you. Bottom line is if you are the focus target, then just keep running around that pillar while your teammate goes to work. If your health starts to drop and they have a priest (holy), run to him, HoJ, bubble, heal. You will want to do this to avoid mass dispel.