they're nice, i'm using half a pro641 set up at the moment. after beating the living hell out of them for about 6 years i have a woofer/mid scratching a little bit. i've also got a pro5.2 set i'll end up hooking up for the time being till i can redo my entire front stage. real clean/smooth/warm sound out of them most the time i ran just 100w a side from a soundstream vga400.2 (the one side is now bridged on the same amp and still take 400w great). woofersetc isnt an authorized dealer anymore- and you can usually beat their price at a local dealer anyway for mmats products.
i've also used infinty kappa perfect, alpine spx-pro, illusion audio, a/d/s, and i've got a pair of eclipse 3ways waiting to install and i would easily choose the mmats over most of them (if i could still find illusion i would love to throw together an active 3way with them)