Working on a shot with dynamic components in the rig and it's running really slow in Maya 2016 with Parallel evaluation? If you tried running the scene through Profiler to identify bottle-necks and you see SetDirty all over it, it could be caused because nDynamics currently don't seem to be optimized for Parallel. You'll also notice the HUD says *Disabled* by Parallel Evaluation.
Here's a quick script to toggle the Dynamic Evaluation in Maya - when it's off you should see a huge speed boost on certain rigs. Autodesk warns that this feature should be used with caution and is unsupported, but I haven't had any issues with it. Oddly, dynamics still appear to run fine and evaluate with it off.
Bonus tip: Putting commas at the end of print statements prints out the text to the little command line at the bottom of the Maya window.