While I am trying to use some of the options in krita. Like changing brush size, also canvas fill it is much much slower than 3.00 version. I am not sure is it only because of the 

Reproducible: Always

Steps to Reproduce:
1.Open krita and make canvas size a3 300 dpi
2. use any brush and change the size via shift click shortcut (also its laggy with [  ] shorts)
3.use fill option with backspace

Actual Results:  
The brush size change is much much slower and jagged. When filling the canvas you can see the brackets filling the color space. 

Expected Results:  
Be faster?