The good thing about this update is that you can take advantage of Dolby Atmos music with any pair of headphones/speakers so long as you have the setting turned to "Always On" instead of "Automatic."

As far as lossless/hi-res - generally speaking, the more you spend, the bigger difference you'll be able to hear (to an extent). That being said...

I have both of these and love them both for different reasons. I've spent more on pairs of headphones in the past and these two top them all:

Sennheiser HD599 - $200

Audio Technica ATH-M50x - $150

I don't have these but I've heard good things (some of which are farther on the cheaper side):

Philips SHP9500 - $60

AKG Pro Audio K72 - $40

Beyerdynamics DT 770 PRO - $150(ish)

Audio Technica ATH-M40x - $100

Other than that - you can google "best budget headphones" and there's a ton of lists. For audio stuff I'd stick to What Hi-Fi?, Crutchfield, Wired, and RTINGS as much as you can for the most reputable reviews. There are a bunch of Reddit threads discussing (read: arguing about) headphones, too. Happy listening!

Just noticing the 250 ohm version is only $170 on Amazon. Good deal for the 80 ohm version though.

I'm really sorry you missed out on the MassDrop 6XX's, but for the money I don't think you can go wrong with Audio-Technica MX-50, Sennheiser 595-C, or Beyerdynamic DT 770 PRO, 250 ohm. Of these I like the Sennheiser the least, but for a bit more money the Sennheiser 598s sound noticeably better if you don't mind open back which will bleed noise.