I had the M8... I definitely prefer the stock look and feel of the Moto X. My personal opinion on most of these new devices is that they put TOO many bells and whistles in them. Some things are good, but I disabled most of them in the M8, including their launcher. I did like the speakers, but the Moto X has very good speakers for what they are... you can at least hear people you are talking to using the speaker phone, unlike the S4. As far as the camera... for a smartphone it's pretty good... it's a smartphone camera.
Plus the Pure Edition is the greatest... no carrier bloat.