Pros: Clear, unoffensive sound, comfortable, good bass, huge length of cable (great if plugging into a stationary amp)
Cons: Cheap plastic, not great looking, Padding on ears and headband made from some random material, huge sound bleed (and they only look to be semi open!)
I picked these Nakamichi headphones up from Donny B's, an electronic shop in Kenora, Ontario. I'm quite sure they are a Radioshack for the most part. I am not sure if they are around anymore, because they were selling everything away when I got the headphones, including these headphones. I got them for $20, and he told me they were originally $150. I can find reviews or sales of this headphone on the internet, so it is not common it seems.
The sound is decent when amped, although from how quiet it is on the E07K, even on 12 gain, they are clearly high impedance. The E07K powers them at 50-60 with 50 being the level of sound I like and 60 being a bit too loud. They have decent bass, mids and highs. There is nothing that stands out, so they are neutral. They are comfortable. The issue with the sound is that even though they aren't open back, the sound to someone standing next to them while they are on your head is nearly as loud as it is to you, who is wearing it. Even holding them together and covering the semi-open backs does not muffle the sound, which is odd. They are comfortable, despite the fact that the pad are hard and made from something that isn't even vinyl, just some sort of coated foam that was cracking off when I opened the headphones. The headband is the same.
Quality isn't great, other than the cable, which seems pretty tough. The plastic is thick, but looks like it would crack easy. Also, the previously mentioned pad material, which isn't even up to par with the Sennheiser pad material (a material that I found to be way to thin and will likely rip easily).
Overall, they are great for $20, even for $100, just taking sound into account.