I saw the formula for the hit points you gain when shrine, it is 10 + 3 * (level + maximum score in Heal/repair of a nearby party member) - from ddo wiki.
Well, the problem is that its not fair for characters with many hit points like fighters and barbarians, even with a high heal.
Lets say you are a barbarian with 600 hp at lvl 20 and there is someone with heal=30 near you when you shrine, you will gain 160hp, or 26,7% of your total life.
My suggestion is to change this formula for another that includes the porcentage of the characters total hp. Something like 20% + 1% for each heal point (same for repair).
With the new formula you would gain 300 hit points, which is a good value for someone with 600 hp.
Thank you for reading ^^