Well I normally listen to/prefer IEM's and have stuck with my Shure SE846's now for a couple of years as still love them. I keep trying headphones as I'd like a pair for when my ears get a bit sore but never happy with them as find SQ no good or too heavy or make my ears hot etc. This year I tried some B&W P5 and P7W; some Sony 1000X and a short test of some HD800 but wasn't bothered about any. My HD660S just arrived and immediately put the smile on my face. These are the dogs danglies!! Super light, comfy and best of all nearest SQ to my SE846's I've had. Materials used to manufacture are not to B&W leather/metal standard but OMG sound amazing. The design is actually very good so not surprised it's little changed in over a decade. Never tried the HD600/650 so these have made me realise what all the fuss was about. Keepers for me to compliment my SE846's for use at home. My Dragonfly Red drives them beatifully but Sony ZX300 has to be on near max. Personally would have preferred shorter cables but that's because I'm only out of a portable player or PC.