What about paintbrush size changed through a slider on the tool bar at the top?

Hi!

I think that the existing option of right-clicking with the brush tool to get a brush panel right under the cursor, with the requested slider in the top position (resize the panel if it is not next to your cursor) is a better solution than having to travel all the way up to the Option bar.

You can scrub zoom if you hover over the 'Size:' text in the Brushes window. You must leave the brushes window open. You could change it and put the scrubby zone over some text on the options bar at the top so you wouldn't have to leave the Brushes window open. Also, you could show the brushstroke on the option's bar so you knew which brush you are using.