Help for ATH M50 or ATH A900

[Acualux]

Hello, first of all I want to indroduce myself.
I'm Acualux and Im happy to be in this superb hi-fi community.

I'm taking the first steps in the "better headphones world" and after reading posts and posts of this forum and reviews (almost all at HeadRoom), I'm between the ATH M50 and the ATH A900.

They fulfill my expectations on a headphone almost all for gaming and secondly for music (I LOVE 70s, 80s and firsts 90s electronic music )).
What I'm after is some headphones that are noise-isolating, good at spacial positioning and that have crispy but true sound for about 200$.

I will connect them with an A40MixAmp for gaming so I think that will be sufficient as far as I've read.

I will appreciate a lot some opinions and advices about which one is better, because I've read that the M50 is a bit less comfortable for long sessions, but has good bass.

By now I would go for the A900 but I prefer to wait and see some advices.
I will be happy to hear about other choices too.

Many many thanks for your help and I hope I can share my experiences shortly with the community in this new world to me .

PS: Hope you don't mind my english faults.

[1Time]

I suggest buying the M50, which sells in the U.S. for ~$110 shipped. I have owned the A900, and I don't think "crispy" describes how it sounds. FWIR, the M50 would be more detailed and with better bass.

[Acualux]

And how it is in terms of comfortability? Any experience with 5+ hour sessions?
Also why is it cheaper then? I don't understand, sorry .
Althought the M50 seem pretty nice...