Build & comfort: It is great. The weight is on slightly heavier side (a bit more than ATH-M50), but the ear pads especially make it comfortable. Wearing them in summer right now will be a little better than ATH-M50. Coiled cable is nice too.
Sound: Loving it. Bass is smooth and tight and the treble is not harsh at all. The mids sound balanced and vocals sound forward and clear. They seem a bit brighter than ATH-M50, which I like. The sound stage is also a bit wider than ATH-M50, which is expected and great.
Impedance and type: All my concerns about higher impedance and semi/open back were pointless. Komplete Audio 6 MK1 drives them easily and brilliantly. In fact, I just needed to push the headphone volume knob marginally higher than the ~9 o'clock position I was using for ATH-M50. It makes me wonder why people with decent audio interfaces would be spending so much on external headphone amps and cables. I will much prefer saving the money and additional setup hassle. They being semi-open back also are not at all a problem. In fact, I would have be fine with fully open back too.
Overall, I would say that DT 880 Pro have a great sound and now I recommended them too. Don't worry about headphone amp if you have a decent audio interface, as you should not need any external amp. Also, if you have a dedicated studio bedroom, semi-open or open back shouldn't be a considerable problem at all. There may be some cons, but it make take some time to find them. Until then, I will enjoy the pros. Thanks to everyone, especially those who recommended DT 880 Pro to me.
Next, I would love to get a pair in the future that are fully open back, have lower weight, and complement ATH-M50 and DT 880 Pro in terms of sound and soundstage/imaging, but are in a similar price range or only a little more expensive. Sennheiser HD 600 or HD 650 probably? Any suggestions are appreciated.
