Hi Tom - From a mixer's point of view, the Bricasti is certainly a large step up from the M3000. I had an M3000 for a little while many years ago and never felt like it blended particularly well or sounded all that good. I replaced it long ago with a system 6000; a much better (and very flexible) piece, and I've also used the Bricasti a bit and like it very much. By the way, you could probably get a System 6000 on the used market these days for *cheap* and it'll do all kinds of terrific stuff in addition to reverb.
All of that said, I'd be hard pressed to justify spending the kind of money the Bricasti costs given the quality of many of the plug-in verbs out there these days. If all you need is a little 'verb for the occasional chopped tail or too-dry mix, I can't imagine you couldn't get what you want with one of the Exponential Audio verbs, or Altiverb, or Aether, or UAD, or Waves H-Verb, or... I mean there's a *lot* out there these days, and many of them sound really good and would be much cheaper than a Bricasti.