Whatever. Wimpy to say the least. 25% FAH! I get better than that on one enchanted piece of equipment. Apparently Shalidor wasn't just a mage, he was an underachiever.
All of Insights Scrolls I acquired not only cut magicka costs in half but also granted a big boost in spell power (equivalent to Alchemy Elixirs).
The ability (albeit temporary ) to cast twice as many of your choice of Destruction spells at 50% more damage can`t be considered wimpy.
The Illusion scroll boosts the duration of effect as well as level affected.
Alteration scroll really helps with Dragonhide by making it less costly and extending it`s time limit
As for equipment only Dukaan/Zahkriisos/Ahzidal masks increase magic damage from spells (25% for their specific elements)