I seem to recall hearing there was was difference, as in you could stun/disarm while holding a spell book, but not while holding a runebook or vice versa Can anyone confirm? If not, I will test, but I'm at work and figureded someone would know
You can ONLY stun punch with a spell book. System message says you must have your hands free to attempt to stun your opponent., with a rune book in hand. Spell books > Rune books