I think a good feature for Photoshop would be for the default size of the brushes to be stored in memory so that when you augment the size of the brush it treats the default size as the fixed point so when you go up or down a size it doesn't forget the default size while you do this. For example if my size is 17 px. If I press up a size button it goes to 20 px but if I press down a size button it goes to 15 px. Instead with this feature, it remembers that the default was 17 px and so it goes down to the 17 px when I press the down a size button from 20px, then to the 15 px after pressing the down a size button again at 17 px. This would be useful because it allows artists and people who use brushes to not fear losing the default size when working.