There is a difference.
Rejuv is a front-loaded HOT; Healing Trance is a channeled heal.
Rejuv places a moderate heal immediately, then heals a small amount every 3 seconds. It heals slowly, can be cast on the run, and you can move/cast while it is ticking away.
Healing Trance gives a moderate heal every second. It heals quickly and cannot be cast on the move. Healing Trance is like a healing version of our Telekinetic Throw.
Both spells have their place.