As for the headphone cord, it seems pretty durable. The two cords at the top are thinner than the single cord that terminates in an L-shaped plug (L-shaped plugs tend to more durable, though you may have some trouble getting the plug into a headphone jack if you have a tough case on your smartphone or one of Mophie's new extended battery cases for the iPhone). The inline remote/microphone is your typical Apple friendly three-button remote. It works just fine with iOS devices but won't fully function with most other smartphones.
The headphones ship with a basic carrying bag. While you might expect something a little fancier with $200 headphones, it's fine. Alas, when you have headphones that don't fold up or fold flat, all you can really do is stick them a bag.
Sol Republic's original $99.99 Tracks headphones stood out for their strong bass. The Master Tracks also deliver plenty of bass but it's not accentuated quite as much. While I wouldn't go so far as to call these neutral, balanced headphones, they are better balanced than the Tracks, offering better clarity and smoother, more refined sound.
What's a little weird about them is that they sound more detailed at higher volumes. At lower to more middling volumes, the sound is a little underwhelming, but as you crank up the volume, they gain some sparkle and have more jump to them. They can't match the clarity and open, more spacious qualities of the Audio Technica ATH-M50s. But they do have big, punchy bass, and they're the best sounding Sol Republic headphones I've heard to date.
In terms of what music the Master Track go well with, the short answer is bass-y music. Techno and hip hop are in their sweet spot, though they also sound good with rock tracks. Not surprisingly, these aren't tuned for classical listening. Then again, I don't think Sol Republic is targeting classical listeners.
The original Sol Republic Tracks are one of those headphones people tend to love or hate. I pointed that out in my review, saying that if you didn't like big bass, they weren't for you, and they wouldn't fit everybody equally well.
Overall, the Master Tracks are a more appealing headphone -- both from the standpoint of design and performance. While I don't think they're super comfy, they're more comfortable than the Tracks (at least for me). Their sound is also more refined and their strong bass won't overwhelm you.
I can't call them a fantastic value, but now that their price has come down to around $150, they're a better value than they were when they first launched at $199.99 and are easier to recommend, especially if you're looking for a more affordable alternative to the $300 Beats Studio (2013).