I dont have much experience with over ear headphones except for auditioning various models in shops but I have a lot of long term experience with hifi in general and also with IEM type headphones.
My setup is : Asus Xonar D2 > Cambridge Audio Dacmagic > Nad 316BEE and I am using the NAD headphone jack (Suprisingly good btw)
When I first put these on I was a little dissapointed because they sounded rather "crispy / crunchy" and clinical if you know what I mean lol.... But after 10 hours burning them in and a few EQ adjustments they sound IMO Stunning!
The top end is very good with a huge amount of detail without ever becomming harsh.... Imo just the right amount of treble (I hate over emphasised harsh treble).... The midrange is also extremely good... very rich sounding and well balanced imo... The lower midrange seems to have been boosted which makes them very punchy and musical sounding.... Also the bass is just right.... extremely tunefull and just the right amount (with a few minor EQ tweaks).
Build quality and comfort is also good imo apart from the slightly annoying wires sticking out.... the weight doesnt bother me and I have had them on all day with no real discomfort at all. I also think they look nice... High quality and professional looking.
Overall I would definately reccomend these, for the price they are EXCELLENT value for money imo.... Initially I thought they were a bit clinical and a bit "crunchy" as I said before but from 10 hours burn in that has pretty much entirely dissapeared. Also people seem to say that they dont need an amp but playing them through my Sansa clip (not great I know lol) compared to my Nad amp is a very big difference. Overall an extremely well made, well balanced, excellent value, sweet sounding pair of headphones.