I bought these from recommendations that they were similar to the K81DJ. And, unfortunately, it didn't turn out that way. In my personal opinion they are overrated in that they have a creaky, washed up sound quality. The bass is very punchy, but after listening to some better gear for reference, they don't offer much bass extension. The mids are plain terrible--and might possibly be the worst midrange I've heard. The only saving grace they have are the highs. Pretty comfortable, way more comfy than the K81's. Good portability marks, they have an in-line volume control and fold up. Isolation is pretty good too. But the sound quality is sub-par, even for this price range. (My UR20 sounds the same or better...) I will give credit that they are better than the very crappy JVC HAS350B, but that's it.

Spending the extra $20 to get the K81DJ is worth it.

These are currently available for around $40 delivered. They compare price wise to the Senn PX100 and Bose Porta Pros. That is where the comparison ends. These are closed back supra aural poratble headphones designed and marketed to the iPod generation. They have a slightly warmer than neutral sound, great bass punch, good mids and good highs. They are not nearly as bassey as Porta Pros. They are not bass head cans. They provide some outside noise isolation and do not leak sound to the outside world. As good as the Senn PX100s are and they are great with unamped iPods for many reasons, these little cans sound much better. They present much more detail across the sound spectrum, they have much more bass impact and go lower than the Senns. The PX100s are ear bud beaters and are just unbeatable for what they are but these Philips cans are PX100 beaters. I would not wear them outside walking or hiking like I do with the Senns but for indoor listening on the go, they are my go to cans.