HOWEVER
It can also be a pain in the ass if you use summon atronach/dremora lord a lot. There are bugs with the spell absorb effect... if you have 80% spell absorb from stone and perk, then you have an 80% chance to completely fail a summoning spell, as you are considered the target of the spell. There is also a bug where the circle of protection restoration spell also gets absorbed, effectively healing hitpoints and recharging your magicka while you remain in the area of effect... so this is kinda a "good bug", if you wanna call it that. There is a mod (if you're on PC) that fixes the summoning fail bug:
http://skyrimnexus.com/downloads/file.php?id=3352
I use this mod myself, and as a big supporter of using spell absorb and conjuration, I have never failed a summons with this mod. It works.
-Loth
PS Healing spells work just fine, except for the high-level protection circle as I described above.