Recs.
Updated
The PXC 550 is a pair of closed-back headphones with active noise cancelling. Bass reproduction is the strong point of these headphones, and these can work as wired headphones or wireless over Bluetooth.
SpecsUpdate
Pros
Pro Powerful bass with good detail on the mids and highs
The sound tuning of these headphones is focused on the lower frequencies. The bass is quite powerful with good sub-bass extension. Users who listen to a lot of hip-hop, dance and bass-heavy music will certainly enjoy the oomph that these headphones can give. The mids sound natural and smooth, yet the lower regions of these frequencies can be overwhelmed by the powerful bass. The highs are crisp and clear though, which prevents the sound from getting too muddy.
Pro Right ear cup functions as remote
When in wireless mode, you do not need to use buttons in order to control the functions of the headphones. The right ear cup lets you control the headphones through touch gestures. You can swipe left or right for next or previous track, swipe up or down to increase or decrease the volume or tap on the ear cup to pause or play track as well as answer or end calls.
Pro Very comfortable noise-cancelling
Well, first of all - you can turn it off, when you don't need it, so that's great! Secondly, they have it tuned so that it's comfortable and doesn't create the weird headache-inducing effect some other strong noise-cancelling solutions do (Bose is infamous for such a problem).
Cons
Con Hard to tell battery level
It's very hard to tell how much charge you have. Some of the competitors have sound prompt telling you the exact charge level, when you turn the headphones on, this one - does not. There's supposedly a gesture (put finger on the right earcup and hold it for 4+ seconds) after which it tells you something like "more than 80% battery left" but the gesture doesn't always work and it can get quite frustrating.
You can see charge level on your phone when connected but you need to know where to look (on iPhone: the batteries widget, on the widgets page)