I haved used ath-m40fs for hmmm maybe five years now? Replaced both ear pads once and currently I'm waiting for replace "head band" (leather has weared of nowadays). Definately love them! Maybe I should buy a spare pair. Also the ath-m40ds would be interesting with it's even louder bassresponse :D Don't know about m50's though.
Also ath-40fs's are quite close to Focal Solo 6 be's in my room at a bit higher levels, just added lowend on headphones.