Looks good, have heard about them before, but this escapes me, who will use a semi-open portable headphones, unless for some specific application. Its good value for money but then the Creative Aurvana Live, Yamaha HPH MH-120 (MH-220 is one of the best closed headphones out there for the money), ATH M50 and several more are immensely better in my opinion.
Continuing in the portable segment of headphones, with regard to portable on-ears, by 2012, I thought I had found the best with the DT1350s, as they had wonderful dynamics and sound stage for a portable and still to this day is the isolation king, when it comes to headphones. But after listening to the Aedle VK-1 my opinion changed, as the VK-1 had clearly the better SQ in every department sans the sound-stage, which improved massively with amplification.
Now the Sonus Faber Pryma, I got it a few weeks back sounds a tad bit better than the Aedle VK-1, but they are in border line on ear, over ear segment. But the price premium one pays to get a better sound compared to the benchmarks like DT1350/T51/HD26 is huge. To me Aedle VK-1 and Pryma is absolutely worth it, especially if you consider the overall aspect of SQ and looks, but to a lot of people it will not be justified.