As a recent customer I have found a couple of issues that are annoying:
1. The program seems to have issues with a scaling of 3008x1692 on my Mac Pro/Cintiq Pro. When scaled to a smaller size its fine but at that scale its "off".
2. There doesn't seem to be a way of setting a custom scratch disk/autosave directory. I can see the option in the settings to change it and when selected it opens a finder window to select a new location but there is no way to actually set the new location.
Side note*
Paintstorm doesn't seem to recognize the correct number of cores in my system. I have a 12 core system but the program sees 20. I assume its counting threads instead. But it's still off.