I could rant all day about the Beats by Dre / Monster Cable brand.
As far as sound quality is concerned, for the Beats Studio at least, you're paying roughly double what you should be paying for an equivalent set of headphones from a respectable brand. Build quality is poor for the price (£280!) and I know several people who have snapped their pairs in half. Also, the 'studio' moniker is largely BS - all Beats products have a bass heavy EQ which makes them fairly pointless for serious monitoring. They're not bad though for general listening, so people who've never listened to a decent pair of headphones before will probably be impressed. If you care about the noise cancellation, you can do far better for less money.
This is coming from the parent brand Monster Cable, whose business model is dependent on consumer naivety to flog them unnecessarily expensive HDMI cables.
If you're looking a for a good value set of hi-fi headphones, look elsewhere. If you care about your headphones more as a fashion accessory, then they might be for you.
I can't comment on any of their in-ear phones...