Well, I can't afford the HD700, my budget is only $300, so which headphones you suggest me? I mean if you say that the open ones are better for gaming. And are they good for music and movies too?
I don't think you read my post. If you did you wouldn't be asking me the questions you're asking.
And I completely disagree with ZapX629 about the MX50's being I actually have BOTH the M50 & M50X. The M50X has a wider soundstage and better imaging than the original M50's and are thus better in the gaming department than the original M50's. Are they the best, no. And, they won't compete with an open back headphone in the imaging and staging department; most closed back headphones won't, unless you're paying top dollar for them, and even then...
And for the record, the one knock about "open back" headphones is they can sound "thin" (less bass, less presence) compared to "closed back" phones. It's certainly the one knock about on the HD700's. This is why most either love them or hate them. When I first got them I hated them and nearly sent them back because I hated their thin sound. Now that I'm use to them I like them a lot.
That said I'm not here to sell you on either the HD700's or the AT M50X's. I'm merely telling you what I have and how they sound to me. Your ears are yours and you have to find the headphone that best suits your needs... not the opinion of others, mine included. We can give you advice, but the ultimate decision is yours since you'll be the one stuck with them, not us.
With that, I would urge you to Google some video reviews of actual users of the MX50's, or any other headphone you're interested in. I can say I "heard" the MSR7's sound horrid all day long, but that's just speculation as I've never actually heard them myself. Reviews can help clear up the "speculation". Actual listening tests would be even better!
As for me, again... I don't buy headphone for gaming, I buy them for music; and in that vein, I like both the HD700's and AT M50X's for different reasons, and different music genres. And yes, I am a gamer, I just don't prioritize my headphones there.
Good luck.