ATH M50 Gaming Performance question.

Well... I am looking to purchase some headphones for music and regular computer uses. Now I heard from different threads around the internet that these headphones are bad for gaming. Something to do with a small sound stage(Can you increase the sound stage or buy one of those DSS2 or with a software tweak on your pc?) . Well I have Turtle Beaches x32s that I have had for almost 2 years and am I better off keeping them or will the M50s blow them away in every aspect? Also I will be using the Headphones for PC use and mobile too. 
 
Another question I have is  with a small sound stage what disadvantages would you have in a game if I were to buy them?

I've never heard the turtle beaches, but I can comment on the M50s.  They indeed do have a small soundstage, which will hurt your gaming if you're playing first person shooters where hearing the positioning of your enemies is important.  With a small soundstage, it will sound like everything is very close to you at all times so it's hard to gauge distancing in your game.  For RTS games this might not matter at all, but I imagine with something like call of duty, you might want an open pair of headphones that has a much more large and accurate soundstage and imaging.

Is there anyway to increase the sound stage of headphones like with a nice sound card? If that isn't possible than can anyone recommend headphones that have good sound quality like the M50s and a big sound stage? (Under $200?)

That shouldn't affect me too bad as long as I will be able to pinpoint the direction.

If you don't mind sound leaking, open headphones will probably a better option for you because of that larger soundstage. If you don't need bass, I don't think you can go wrong with the Sennheiser HD 598s (currently $187). Madlust has created a great guide to gaming headphones so I'd take a look at that too:
 
http://www.head-fi.org/t/534479/mad-lust-envys-headphone-gaming-guide-updated-9-2-2013-sony-ma900-added

 
 
 

ATH M50s are terrible for gaming. Ive tried. Sennheiser open models and my beyer dt990s work well for gaming.

But my main point was does M50s have a better soundstage?

I don't know how the soundstage is on the turtle beach, but the M50s have very little to no soundstage.  Again, this may or may not be a problem for you depending on the type of music and games you play.  If you mostly listen to rap/EDM/hiphop and play RTS games then M50s will be fine.  If you listen to classical, orchestra, or basically anything that would represent a concert hall and play first person shooters where distancing is important, then you should go for open headphones as suggested above (HD598, DT990).  The AKG K550 is known to be a closed pair of headphones with good soundstage, but is also known to be a bit bass light.

Thanks