Needs to be bigger or resizeable. Right off the bat things seem a little cramped.
The preview size when configuring keyboard/mouse is way too small. The options (keys, easy switch, settings) take way too much space on the left side, I'd rather the preview was much bigger.

As a result the old logi options is much more comfortable to use.

I tested it on a 1366x768 screen size. I can only image things will look even smaller on higher resolutions.