I prefer the outside cover as it keep the RV cooler on hot summer days and keeps the windshield clean. Also, the outside one provides for more privacy (imo) and allows me to adjust the radio easier.
On the other hand, I like the inside one when I am stopping for short times or when it is raining. It works well enough and doesn't require me to go outside in inclement weather, so for convenience I like the inside cover.
So... I have both and always use one or the other, they both store very easily.
~CA