Yeah octopus got what I was going for. You're effectively writing one extra spell list per casting class, since you need to write out 11 levels of stuff per fullcaster and 6 levels per quasi-caster (bard, duskblade). Not to mention new magic item cost algorithms and having to explain DCs.

I'm also not a big fan of vancian magic in the first place, so doubling the dosage doesn't sit well with me.