The M6000 is modestly faster in the Large Model Composite test and a hair quicker in the GPU Composite benchmark. These are tests that NVIDIA previously won, so things aren't changing much here. AMD still has a decent price/performance comparison point in 3ds Max, at least when using the 2011 iteration of the software.
The M6000 generally improves on the K6000's scores here, with one big leap in Large Model GPU performance. The FirePro W9100 is price/performance competitive, but doesn't win any categories outright.
SolidWorks 2013:
SolidWorks is a solid modeling CAD program that's actually manufactured by Dassault, not the all-encompassing Autodesk. SPEC has its own SolidWorks benchmark test that puts the program through a comprehensive set of scenarios.
An earlier version of this graph suggested that the Quadro K6000 had actually outperformed the Quadro M6000, but this appears to be a test artifact. Subsequent retesting showed that the M6000 was slightly ahead of the K6000, though only by a marginal amount. Overall, this benchmark strongly favors Nvidia; AMD's FirePro cards aren't competitive in price or price/performance.