I've been playing with new Krita Ubuntu snap package Version 3.0.1 (git 7c6cf9c) for some days, and I find it slower, i.e. general performance is poorer than the appimage of Krita. I notice performance problems with my brush strokes, moving layers (the layer content redraws, well, quiet slowly). I have Nvidia card with 361.42 driver installed on Ubuntu 16.04. I don't know if Krita Ubuntu snap package works as it should for someone but not for me. It looks as if the snapp package is not as fast as the original appimage of Krita at the moment. So I'm coming back to appimage, although it has some problems with the desktop integration.

The snap is slower because it uses the stock Qt, without the patches we apply for the appimage.

Ok, thanks for your reply, Boudewijn! I now understand.