Pokémon X and Y - Competitive Side

mega sweepers in general are a total menace, their base speed shots to levels unattainable by most other pokemon, meaning you'd need to use stuff with priority to bring them down or something of the sort, have you guys looked at megalakazam? 150 base speed with deoxys levels of special attack (175) your only bet to kill it is to sucker punch it or something of the sort, god forbid it gets a nasty plot or a sub.

I read on Smogon that math shows that a lot of Megas are the same as, if not weaker, than the un-Megavolved counterparts because they lose access to Life Orb (& etc.)