M-80S are lower aspect to the spectrums but are much more stable. not saying speccie 11s are bad, but the m-80s are sic and you dont have to worry bout em. now depends what you are into but if you wanna ride waves then the m-80 doesnt pull u off ur edge like the higher aspect kites like the spectrum does when you go into a bottom turn.
also if it is truckloads of power n grunt for popping and jumping then m-80s are better. the spectrum 11's jump higher tho if you are looking to boost.
the bar is heeeps better on the m-80s, but then its 5 line.
if u are in perth you can have a go of my 12m m-80 i have for sale. i went to them after the spectrum 11s. i am just selling my big kite.