Mewtwo X is woeful pointless due to its Physical movepool being mostly elemental punches and maybe earthquake and Psycutter. It might throw some people off, but if you need a physical uber, there are much better choices in the tier.
Megazard X/Y mostly depends on the situation, I'll say X is better over all since he can be used in more situations as a whole, --- Gamefaqs in a nutshell (http://error1355.com/img/gif/gamefaqscant.gif) 3DS friend code 1161-0910-0692
Both Charizard X and Y are good and both have great points to them and fulfill different roles. It's a matter of preference for whichever you want.
I haven't heard much on MegaMewtwo Y, but as mentioned before X suffers from a lackluster movepool on the physical spectrum and can't fully take advantage of its new stats. --- Official Wyvern Lord of the Awakening Board
Life orb Mewtwo outclasses both Megas. Solar power Charizard has sheer power under the sun but he doesn't work as well as his megas. --- Friend Codes,NN and PSN is in profile People who think I'm Awesome: 17