The M4 is better because of the insane brightness and quality display. Functionally my M1 iPad Pro is effectively the same as the M4, and I don’t really notice the faster chip or weight saving, but that display! You can use it in direct sunlight with sunglasses on. And the pinch gesture on the pencil. And the camera being in the right place. It’s too expensive for sure, but it is just a lovely bit of kit. iPadOS hobbles it artificially, so it is limited to companion device status, but it is just lovely to use. This plus 16gb M3 Air is just an awesome combo!