PLEASE register a click on the on tool buttons on the MOUSE DOWN instead of MOUSE UP.
Currently when you click a tool button the tool bar, it only counts as being selected on the mouse up state. This results in the tool not changing when I am going fast and furious working on a sculpt as I ultimately mouse up when the cursor leave the tiny button region
This sounds like a silly minor thing it is beyond infuriating when I am working on stuff.
Maybe just add it as a toggle check box in the UI Preferences?? Pretty PLEASE?! 
Surely I cannot be the only one who does this.