My PX100-ii's just failed after 3 1/2 years of use... and I immediately repurchased. I am a professional musician and own much more expensive headphones and headphone amps for mixing and critical listening, but these are what I use on a daily basis for exercise, work, and travel.  These paired with a Sansa Clip are the perfect exercise rig!  The accentuated upper-bass/low-mids might not be to everyone's liking, but for exercise and travel I prefer this sonic signature. I love that with the PX100-ii's I can hear my surroundings.  I tend listen at low to moderate levels and, with traffic and other environmental noise, I find that more balanced headphones can sound thin.  I also don't notice cable microphonics while running like I do with my in-ears.  Are they perfect?  Well, mine did eventually fail, perhaps because I got rained on on a recent run, so maybe they're not very water resistant.  But I have been sweating on them for 3+ years and have been rained on several times before, so maybe that's not fair.  They also might start to get uncomfortable on my ears after long periods, so maybe there is a little too much tension or the pads could be a touch thicker, but mine were 3+ years old and I had never replaced the pads.  As for comparing them to the original PX100's... I  remember them being lighter and a tad more comfortable, and I remember being a little disappointed when discovering my PX100-ii's were bassier- but like I said, I grew to appreciate this.  And I much prefer the updated cable configuration (single cable to the left ear) on the PX100-ii's. The 3.5mm plug is sturdy and small (good for recessed jacks) and the cable is a good length.  Lastly, I will simply say that these sound excellent!  They may not be the most balanced headphones, but I find the "thick" bass quite pleasant.  They are great for low level listening and are never harsh.  Even poorly recorded material tends to sound decent through these (which is one reason I would NOT use these for any mixing/critical listening duties!).  IMO this is a case where they "got it right"- I hope this model is still available for the next time I lose or break mine!