Summary: *note the one I have are the new perceptions not the old ones, not sure if there's a difference other than a logo change*
These cans are pretty under the radar, but if you can get them for a cheap price (I paid 50 bucks CAD for these) and you have an amp or a good dac, then they may surprise you.
Pros: Very light and insubstantial. Neutral, textured exiciting sound. Loud without amp. Good detail, soundstage and imaging for the price. Minimal design
Cons: tonality is a bit off, leakage, needs amp/good dac to get good sound, ear cups hard and uncomfortable