Imo, as a long time cold defender, current frostwork is sub par. It has very limited usefulness, as it is single target with a decent cooldown, and works best as a preventative measure. The max HP caps limit its usefulness further at endgame with accolades and set bonuses come into play. The minimal regen bonus is mostly negligible on most AT.
Making it absorb however allows the power to function at intended capacity from min level into incarnate territory, it allows it to be a 'save a teammate' type power, or 'beef the tank' if needed. Which would actually make me want to use it in more standard situations.
As much as i would like the versatility to heal as a cold, healing is supposed to be the lacking element in this powerset.