Thanks.

I have a few versions of the Garmin Radios as it happens. Some have more buttons and, depending on personal preference, might be visually more appealing.
However, whilst they have a couple more functions, they're also littered with dummy buttons.
The biggest problem with them is that because they're so complex, they really require a pop-up window of some size in order that the buttons can be read properly. Obviously this wasn't an option for this particular panel as visual accuracy was the primary objective.
The blue displays themselves btw, remain pretty uniform throughout all the versions I have.