As of right now as it stands the mechanics surrounding absorbs doesn't offer much value in actual game play. Due to its nature of being a ward, it can be removed using spells like steal ward and pierce and of course roshambo spells via pvp. However the reason its devalued is probably due to low number values and high pip cost.
An effective way of changing absorbs is have it (absorb) 25% of the damage inflicted to the user and covert this damage into a heal over time for 3 rounds. Thus the higher the damage the more effective in heal the absorb will become.