I have both, and the key is to use them with your own gear, as in-store demos often stink, with some in-store demos I've heard having bass EQ'd up heavily.
My opinion on both, as an audio enthusiast: The Studio is better, to my ears. The Pro is too heavy and soft sounding, not to mention excruciatingly uncomfortable on my head.
The Studio (in my opinion) sounds relatively good for a headphone that incorporates active-only operation, as well as always-on active noise-canceling. The thing is that its passive isolation is poor, even though it's closed. And its active noise-canceling is far from standard-setting, and comes nowhere close to blunting the noise its poor passive isolation lets in. With the exception of headphones I use for travel/on-the-go, I don't expect my closed headphones to necessarily have strong isolation from ambient noise; but when you put an always-on active noise-canceling circuit on a closed headphone, one might reasonably expect it to.
The Bose QC15 earns its price by being one of the best over-ear headphones to use on an airplane or in a datacenter (or other places with loud, droning noisy backgrounds), especially for those people who do not like wearing in-ears. The QC15 is exceptionally effective at canceling noise. I wouldn't buy the always-on active-noise-canceling QC15 for listening at a quiet desk, though. And this is where the Beats Studio is a bit weird. Its sound quality doesn't come close to earning it a spot in my sitting-at-a-desk headphone listening roster; and its poor isolation doesn't earn it a spot for use in noisy environments.
So the Beats Studio is not a headphone I recommend unless someone is insisting on a recommendation of which of the Beats headphones sounds best--some people insist on something by Beats for the style/brand, and if that's their thing, who am I to fault 'em? Yes, on Head-Fi, sound quality is what we care most about in a headphone; still, most of us buy at least some type of something (like clothing, shoes, cars, etc.) because we like the style and/or brand. If someone really wants Beats specifically, the Studio is the best sounding of all of the Beats models, in my opinion. (I should note I haven't heard the Guetta one yet.)
To answer your question: My guess is that the Pro was designed to be bassier sounding--if so, then mission accomplished. To my ears, though, it's definitely not an upgrade to the Studio.
Now maybe I'm missing something here, sneaglebob, but what about your post is URGENT?
