I can't help you with the comparison, unfortunately, as I've only briefly heard the M40x (I do have the M50x, which is good, even though I don't listen to it much (I have others that I prefer--mostly open cans)). There is another can in your price range that I think is probably a better option than the Audio Technica and that is the Takstar Pro 80. It really, really has good sound quality, especially in its price range. Very hard to beat. You might take a look at it. Other than that, you might consider ordering both the M40x and the Skull Candy and try them out, then return the one you like less (you could do this with amazon, which has a great return policy). In terms of a final buying decision, it matters a lot less what we think than it does what you think. Best of luck to you!