Mega Ampharos: This is probably the worst mega evo imo, while it has a high "165" SpA, it pitiful speed is now even lower, and while it may have better defense, there's a lot fast-powerful ground types out there, like Excadrill or Garchomp, as well as the new fairies, it still can be easily OHKO'ed without getting the chance to hit due to it's pitiful speed, which isn't enough, combined with the fact that there are other mega evos giving competition, it's not precicely going to be threat as some ought to be, specially in OU.