i have a janome MC11000 and an MC6600P. i've had the first for nearly four years and the second for nearly three.
i am very happy with both.
i will confess to a niggling yen for the 12000 waaaaaaaaaaay in the back of my mind.
so far, though, i am happy enough with the 11000 to ignore it. (who knows how long that will last. LOL )
my favorite thing about the 11000 is the way the embroidery unit is built in. the only thing i have to remove (and therefore risk losing or damaging) is the hoops. it's also excellent for piecing and quilting - either straight-line or free-motion. all of that will be true of the 12000, too.