Hmm, this is an interesting thread.
Firstly, I'll say that yes, the M50's are the only can's (full size) that I own at the moment.
I'll also mention that I apparently have the new redesign. (Which if what you say is correct, I'm glad of, because I'm starting to think I want some thing a little more... I don't know... Grado-y now.)
I'll also say that I paid a touch under $100 for them.
Now I have a question, what exactly is the price that you're comparing them at? $100? $120? or that *high* price of $150?
I certainly do enjoy them but as I've listened to them more and more, I start to see what I want in my next set of headphones, but that is not to say that the M50's don't do well what they do. That is to say, if you like the way they sound, you'll really like them. I'm just thinking I prefer a faster, less bass-heavy 'phone for the music I listen to. But for the time I've had them, I've certainly loved them.