Not to sound stupid, but could someone explain why the beguiler's lack of 5th+ level spells that do anything to enemies who are immune to mind affecting doesn't hold it back from reaching tier 2? Particularly in regards to the common claim that it's better than an equal leveled sorcerer, who is just as capable of using thinks like runestaves and UMD, and indeed might well be better at it given that UMD keys off of charisma and isn't needed for anything on the sorcerer spell list. Can you really expand your spell list adequately without PrCs?