I'm going through the same thing.
My daughter's puppy ate through the cable of old faithful ATH M40s I keep at home .. they were getting due for retirement anyway.
Got a pair of the newer ATH M40X to see how I liked them.
I'll probably replace the cable on the ruined ones, but it was a perfect excuse to buy a new set! And I played it perfectly; when the wife told me what he did I said "Well there goes $100", walked in and looked at them, then ordered new ones. She didn't say a word.

At home I liked the new M40X a lot. A little more bottom than the old ones but not too much (I think the M50s have too much).
Then I went and did some recording at Barry's and suddenly it was too much.
Same soundcard and headphone amp!
I think maybe it's how Barry has the mixer set on the input side that could be doing it.
Anyway, I feel ya, new phones take a bit of getting used to.

I still have my second ATH M40s at Barry's, so I guess I'll try to get a little more time out of them and keep the new ones at home. The old ones will need new pads pretty soon though.

Make your sound your own!
.. I do not work here, but the benefits are still awesome