Depends if you want to wear a helmet or not. Though 2 Stones active is pretty bitchin'.
If I was doing a dwemer themed character spellsword with fire magic and dwarven crossbow, I'd take the staff because I'd rather have the helmet.
If playing a Mage, the crown.
If I'm playing an assassin/thief and have the DB gear, I'll keep the cowl and go with the staff even if I don't use it much because followers can't benefit from the crown since they can't utilize stones and can use staves.
It depends on your gear, losing a helmet (and the armor perks like Windwalker, custom fit, etc).
What are you playing and the amount of perks you will lose for not having a helmet slot filled?