I really loved how I could swap tools with my left hand as I was drawing in the old UI. Any possibility you can bring that back? It was the #1 reason why I didn't like "painting mode", when the tools are at the top and in a weird spot to access. I do like how the sliders aren't on the bottom anymore; no more accidental changes while drawing due to failed palm rejection. 
Also, options for moving the brush/color settings to the left side would be nice as well!