The CheckBox renders a small checkmark when IsAnimated="False" but normal size if IsAnimated="True" on Windows. It's quite noticeable if If you scale up the Length to say 40, the checkbox scales up but the checkmark doesn't scale, leaving it weird looking.

When setting IsEnabled to False, the checkbox is still enabled (on Android) and can be checked.

RadCheckBox CheckedSymbolColor doesn't reflect the value on Windows. The default value is displayed instead.