So small update:
- The Drivers of my Bamboo Fun PEN & Touch (pretty old) are old but uptodate. Which is not nessecarily a bad thing, as old drivers maybe are also less buggy.
- I also observed the Hardware Usage (AMD FX 8350, 16 GB RAM, AMD R9 290 Tri X) if I really just go crazy it maybe touches like 50-60% CPU usage, which produces a small input lag (totally understandable) but goes down to 2% or something again.
The problem is also really hard to reproduce. It is just not responding from time to time, so that I do have to restart the program, but works really good apart from that.
I also use a 4k screen, if this can have something todo with it.