After playing Skyrim, I purchased Oblivion. I thought the Altmer were horrible in that game. Add in the fact that they had a 100% weakness to magic, and that sunk the class for me
Actually, not too long before Skyrim came out, I went back and finished Oblivion with my first character, then started a new game with an Altmer Mage with the Apprentice sign. Enemy mages could be a bit of a danger, but damn, he was pretty good in the magic department. I got used to summoning things to tank for me while I dealt magic damage from a distance, and did pretty well.
The Altmer weakness to magic plus the Apprentice weakness to magic was pretty tough at first, but the combination of Altmer and Apprentice made for a really good mage overall.