Deeemn, that is reeeeeally lucky. (I mean, for him, not for you :v ).
I've been experimenting with the card and I think that it is OK, not like, super broken, but generally OK.
I mean, yes you can get pretty insane cards from the BMR like the savior Zombot 1000, but you generally want to play as many zombies the turn before to try to get the most value out of BMR.
(I mean, its not the same you transform just 1 zombie rather than 5)
But this leaves you wide open for some AoE clears, specially from the Kabloom classes.
Also it is pretty expensive, so you can play other insane cards of your own for that cost...
I don't know. I havent seen many decks that included that card, but at least I can tell you that Super Brainz really lucked out.