Also, since you can’t currently merge the spellbook with cleric. Sorc has the advantage of added caster levels. As, we’ve discussed on other threads, once you hit CL 25, you can make per round buffs, 24 hours with mythic feats. Also, arcane has the shield spell(useful until you get bone shield), mirror image, transformation and displacement. Making them one of the best tanks available.
In addition, the ability to use charisma as a main stat will likely play a big role if you are turned into an undead creature type at some point. Then you’re using charisma in place of your constitution stat.