+1
When the top is up, the rear view is extremely limited by the wide C-pillar region and smallish rear window. The coupe does have a slightly better view.

 

I had one installed for top up reversing, only drawback is the oft mentioned dual touch requirement on your screen. Now if Pearl could be used both front and back, they'd have a winner!

 

I find that modern reversing sensors do a great job. I don't have any problems in my XKR using a combination of mirrors and the sensors to reverse. My wife's Audi S4 wagon has a reversing camera but I don't bother looking at it as the sensors on that are great as well.

My spare car, a Subaru Outback, beeps when you are reversing but doesn't actually have sensors so it is easy to forget that the tone isn't going to change when you get near objects!