I bought one a while back when they just came out. They are based off of the old Eugine Stoner "Stoner" machine gun system that the SEALs used in 'Nam. The rifle shares all of the "Stoner"'s pluses and minuses. They are:
PROs
- modular system, change out uppers to become rifle, carbine, top loader, etc.
- takes all AR/M16 mags, including BetaC and drums
- gas op like ARs but gas system is adjustable
- very stable platform, good accuracy with full size barrels
- just as big and weighs just as much as an AR
CONs
- expensive! Mine was $1,500+ when I bought it
- must be thouroghly cleaned and maintained like an AR
- parts are more expensive than AR parts (just like the overall gun)
- top feeder is awkward unless you have shot top feed before
- gun is a little nose-heavy
My overall opinion is that the M96 is a very good weapon as an alternative to the AR15, if you can afford it.