These are some interesting plugins ... nice that the MM series seems more versatile as opposed to the other Artist Sig plugs which are meant to be instrument-specific.
That being said, right now I'm seeing these more as time-savers than anything really new. The reverb is good, but is it clearly better than, say, Valhalla? So far, my ears are saying no. What makes the MM reverb cool is the integrated compressor and other effects. But unless you're really in a hurry, these can be added to any reverb separately.
The other plugs are similarly well put together for common tasks, but could probably be replicated with other tools you already have. I was able to do similar things with Waves' V-series EQs as the MM EQ did, for instance. Same with the Triple-D. The distortion box wasn't my cup of tea, and the Tone Shaper, while useful, didn't wow me but I did have some fun with the MM Delay plugin. It includes a nice reverb, so this may be the best value of the bunch. Looks like the plugs aren't available separately yet, though.
Anyway, it's always good to have new tools out there. Kudos to Waves for keeping 'em coming.
Cheers,
Eddie
EDIT: after playing more with the EQ, I must say that whatever curves he's implemented in there, they do result in some good sounds. This plug is a winner in my book. Not that it's better than everything else, but if you could only have one "character" EQ, this would be a good choice.