If you switch from a tool to another while holding the tool's shortcut button (i.e : switch from brush tool to eraser tool with a shortcut, but holding the "e" key while erasing something) make photoshop toggle between those tools. Some people may make use of it, but not me. In addition, the keyboard shortcut often lag, making photoshop do the toggle out of nowhere. It's really frustrating especially for Illustrators since I change the brush and eraser tool often. Please do something about it.