Hi, I just got the new Deco Pro which I really love but, I started using with Krita with no issues, tablet was responsive, and no lag at all, even working on multiple layer drawing.  

Once I opened Photoshop things went downhill, I thought at first it was PS as the new version can be laggy at times, but I fired up the two previous versions with same result.  Once I uninstalled the driver for the XP-Pen Pro, Photoshop became it usual self again.  

What I noticed it brush strokes will lag and if I used any of the express keys or even the pen buttons, that is when things started to go wrong and PS will hang "thinking".  It was quite frustating, I would draw and nothing will show right away, about a minute later I would see the lines being drawn.  

Anyway, the driver did work fine with Krita, so my guess is that there is some issue with Photoshop and it is not liking the driver.  Wanted to give a heads up, just in case is something that needs to be fix in future update.