Pros: The bass is really good without being overwhelming, they fold small, they feel solid
Cons: Poor isolation makes them useless in metro for example. Also, please don't use these in a library.
I see two big positives to these cans:
1/ the sound (nice fun V-shaped sound, a bit forward but not "in your face")
2/ they fold pretty small
As the isolation is not really good, these should be used in places where noise is not an issue. And this is for me the problem, I cannot use them in transports. This becomes a plus for people that plan to use them when they walk in the street as hearing what is happening around can save your life, but even then I would appreciate a little bit more isolation.
Also, I am wearing glasses and the comfort was an issue. I had HM5's pads on them which helped (but this changes the sound alot -> less bass) and even the isolation was improved, it was still not enough for me.
So for 50$, if you don't need isolation, these are nice little headphones to be tossed in a backpack (what a pitty they don't come with a pouch...).