meh
justin, when you use CM, the stats of both your SP.ATK and SP.DEF increase by 50% (1 level) so mewtwo's scari 400+ SP.ATK would become a friggin scarier 600 SP.ATK ... this is after just one calm mind, imagine 2, or 3, *shivers* now all you gota do is use recover to get all the damage dealt to mewy back to green, and sweep away; with mewy's speed, fat chance they'd get another hit out of him, and becoz of CM, his special defence is decent too, the only thing you gota worry about are strong physical types; they're often extremely physically biased, so a neutral special attack could take em out in a hit if mewy pumped 3 CMs...
... a mewtwo with 3 attacks maybe versatile, but it won't be able to take on the stronger tanks... and once it's defense has been exploited, mewtwo goes down easily *frank skillfully dodges a bullet as he says that* yes i said MEWTWO GOES DOWN EASILY TO PHYSICAL *frank executes a back flip in order to dodge a ray gun beam shot* ... ATTACKS *frank side steps to avoid an RPG rocket* ... yeah, as much as RJ would like to deny it, mewtwo isn't all that powerful as long as it can't take the opponent down; it can't take much damage... without CM, it could even be killed by dark types with just crunches or bites... without recover, cumulative damage will bring it down eventualy... it doesn't take a shedinja to take a mewtwo with 4 attacks down... blissey, snorlax, slaking, anything with sufficient attack strength and a decent hp/sp.def could take mewtwo down fairly easily... the list goes on with metagross, tyranitar, dragonite... oh just basicali n e good poke > special sweep mewtwo...
CM + recover isn't defensive, it's smart play; a dead mewtwo isn't a very offensive one now is it -_-"