Pros: Cheap, great vivid sound
Cons: Fold into a circular shape, rather than a flat one. Might pulls some of your hairs, specially if they are curly due to the metal band.
I picked these up when I was living in Belgium when I was looking for a cheap and durable portable headphone, that wasn't in-ear, and I was certainly not disappointed.
These headphones have almost the same level of clarity as my Grado SR125i but have a considerably more pronounced bass and are, quite simply, a lot of fun to listen to.
The form factor is quite interesting, because rather folding as most portable headphones, the PortaPro bend into a circular shape, around the size of a tennis ball, which makes them a bit inconvenient to carry if you intend on carrying them inside a laptop case.
I've used these headphones while riding a bicycle to work, I've used them while running, while working in public places, and although they are not ideal for all of those situations, they are certainly more than passable, and give you very enjoyable listening experience. Just remember that these headphones do leak sound, so they might not be ideal for commuting.
When I want to go for a walk, and I don't feel like putting the "rubber band" and the DAC around my iPhone, these are the headphones I'll usually grab because I'm certain they'll sound great, regardless of what I plug them to, even though their sound does improve noticeably when you plug them to a DAC.