My thoughts exactly. I thank the Adobe staff for their suggestions. It's great that there's some sort of fix, but I imagine plenty of other users with the same problem simply don't know how to troubleshoot it, and/or haven't stumbled upon this thread yet.
For clarity on the specific issues I'm facing:
- Cintiq 13HD with Wacom 6.3.8-4 drivers
- Photoshop 20140730.r.148 x64
- Win 8.1 x64 - latest updates installed
If "Use Windows Ink" is checked, the pen right-click in PS won't activate unless the pen is moved (roughly 15px from the initial click position) whilst holding the right-click button. Single clicks on GUI elements - such as drop-down menus - only register after the pen is lifted from the screen or moved by a similar arbitrary distance, rather than as soon as the pen makes contact.
Un-checking "Use Windows Ink" fixes these problems, but the pressure and tilt sensitivity cease to work shortly after. In the Wacom tablet settings I can see that the tablet is definitely still reading pressure correctly, it just stops working in Photoshop.
I understand this may be an issue with Windows Ink more than Photoshop, but even so - it shouldn't be the end-user's responsibility to fix such compatibility issues. It was Adobe's decision to make the shift to the new drivers.
For now I'm going to try the PSUserConfig fix - but even if that works, I don't think this should be written off as a 'fringe' problem by Adobe. It seems common enough to warrant more action than a few forum posts.