Hi there Head-Fi!
I have had experience with some entry-mid audiophile headphones (I own the Sennheiser HD 280 Pros, HD 428, and Audio-Technica AT-A900X.) I used to have a pair of AD700s. I loved them to pieces, but had to sell them off to pay for some bills. As a result, seller's remorse and I miss open-backs very very much.
I was going to go buy the AD700Xs as a result, but after trying the AD900Xs, the fit just wasn't the same (the wings seem to be much more loose.) I just remember the AD700s having the best comfort I have ever been graced with in any headphone.The original versions seemed to have perfect tension, but the X versions seem to be looser. I even have the rubber band 'mod' on my A900Xs to keep them on my somewhat tiny noggin (but it does interfere with long-term comfort.) As a result, I wasn't really a fan of the AD900X.
I also figured I'd try to match my A900X's quality in some way. I'd like something that's bit of an all-rounder (I listen to a little of everything, but my preferences lean to metal and occasionally hip-hop quite a bit.) Some lacking bass doesn't bother me much (I used to listen to, and enjoyed a lot of metal and hip-hop on my AD700s, which had barely any bass to speak of,) though I think the more the merrier. I'm more about mids and treble than anything (I go to my A900Xs for more bass-heavy stuff.) Comfort is first priority for me though. I can sometimes sit at my computer for hours on end depending on what's going on. I'd also like to benefit from a solid soundstage, as I'll listen to some classical/jazz stuff along with the occasional big video games.
My main budget is $200, but if someone can suggest a ~$100 amp (or anything) required to drive them then I can jump it to $300. Otherwise, it's going straight into my PC Motherboard (MSI Z87-G45)
Some of the stuff I have been considering though:
Sennheiser HD 558/598
AKG Q701 (would need amp recommendations.)
Grado SR225i (been kind hesitant with these since they seem to be on-ear. Long-term comfort for on-ears is a shot in the dark for me.)
Beyerdynamic DT990 250 Ohm (again, would need amp recommendations)
AT-AD900 (I wasn't a fan of the X version's fit, and they can be found at a semi-acceptable price.)
I'm also open to any other suggestions if y'all have any (I don't plan on making this investment possibly for another month) then feel free to leave them below and I'll take a gander. Thanks!