I've done the same thing with my second monster which i got from mike....My setup is:
8ight-t
neu 1515 1/y/f
MMM (all the default settings except 20% drag brake and low motor timing)
5s 8000mah true rc lipo
CC BEC set at 6.0v
And so far after taking it to the track and bashing with it over the past 2 days and running the 5s 8000 down to the cutoff (around 45min) my monster is still going strong

i actually spent more time fixing the stuff i broke

after over shooting my landing on the triple one too many times and throwing caution to the wind when bashing

but so far so good....2 cycles through it and its performing awesome!!!!!

and of course i disabled the BEC and am using CC's BEC until my other MMM comes back form castle.....so far so good

a lot more successful than my first MMM

..and castle does have excellent customer service as Joe immediately emailed me about my dead monster and a replacement is on the way