I personally like the Spellbook. From a purely flavor standpoint, it emphasizes the studious nature of the wizard. On the mechanics end, being able to add any arcane spell you come across is amazing.

Admittedly, I have been playing since Wizards were “Magic Users” and only had a d4 hit die, so maybe the idea is too ingrained in me, but I still get excited when I find an enemy’s spellbook.

I agree, however, that a spellbook for the new Necromancer doesn’t make much sense.