I can say so far, after PD10 installing on the following:
Early 2011, 13", 2.7GHz i7, 8GB RAM Macbook Pro
Late 2013, 27", 3.4GHz i5 iMac, 24GB RAM (with attached Thunderbolt display)
With some quick testing with Win7/SP2 and Win8.1 I have not come across any any issues so far.
Overall most apps do seem to open faster and working in all of them seem to be a bit "snappier".
Some of the apps: Microsoft Visio 2007, IAR Embedded Workbench for ARM, LTSpice, ORCAD 9.2,
Visual Studio 2012, MATLAB.
Monday when I really start getting down to some real work in the VMs, I will get a better feel.
At least compatibility wise with the stuff I am working with there doesn't seem to be any issues.
At least for now, no "disasters" or odd anomalies have occurred.