Summary: Disclaimer: I'm not an audiophile, and I haven't tested with high-bitrate digital audio sources. Having said that, I'm completely satisifed with my purchase. I mainly use these for watching streaming video content on PC and multiple mobile devices (laptop, tablet, smartphone), and the audio quality is more than adequate for these purposes.
Pros: Audio quality, cord length.
Cons: May be personal, but can be uncomfortable after extended wear (>1 hour).
Summary: Comes with three sizes of plugs. Try all of them to find the best fit of your ear.
Pros: After switching to a different plug size (where there was a better seal) the sound quality is unbelievable. Great bass for such a tiny ear bud. I actually had to turn the bass down on my mp3 player after switching to these new buds. Not sure about "HD" sound, but its pretty dang good.
Cons: Cord is not very rigid near plug. I've had problems in the past with other headphones wearing out near the plug and the stereo cutting in and out. No problems so far though.
Pros: Great frequency response crisp highs mellow mid-range phenomenal lows soft fitment in the ear, design wont allow full out during a sweaty workout. 3 different sized soft rubber dampers fit even my children's ears.
Cons: Upper range highs could be slightly over pronounced. Easily reduced with equalization.