The XP-Pen X3 Pro series of pens was introduced in 2023.
XP-Pen states it should have an IAF of 3gf. Subjectively that felt accurate.
XP-Pen says the X3 Pro pens should have a max pressure of 400 gf.
My testing shows that individual units can vary from ~250gf to ~450gf.
Pen pressure levels - 16K. Ignore this. it is hype. All you need is 2K pressure levels. More important than this is the wide pressure range (from IAF to Max pressure).
Obligatory 16K pressure level screenshot. This is what it shows in the driver.
There is no noticeable impact on my drawing.
More here: pen pressure
Pen eraser - Only the X3 Pro has an eraser. the other models do not.
Disabled buttons impact on drawing
Good: If you disable the two pen buttons in the driver, and then press the buttons while drawing it doesn't seem to interrupt drawing. I tested this with Clip Studio Paint and Krita on Windows 11.
