Krita just keeps getting better and more amazing!

I've noticed a large slowdown with some layer operations. Just switching layers usually takes upwards of a second and creating or moving layers takes even longer. Even toggling visibility has a noticeable lag. The size of the image doesn't seem to make a difference nor does OpenGL. This lag has been experienced on two computers, one running Windows 8 and the other Windows 8.1 in the 64-bit builds 2.8.79.14 through 2.8.79.18. I haven't seen this mentioned and was wondering if it's known or considered a problem.

Many thanks to everyone who has brought Krita this far and onward to 2.9 and beyond!