It's an easy question: which mirror would you rather have as your side mirror? The standard one, which shows a field of view of about 17 degrees... or the one above it, which shows a field of view of 45 degrees?
Now let's say there's a cement mixer in your "blind spot". Which one now?
Dr. R. Andrew Hicks of Drexel worked out how to get a wider field of view in a mirror, without the usual distortion of the convex "Objects in mirror are closer than they appear" mirror. Look at the silver car in both views to see what a difference this is. It would take some getting used to but I imagine the wider field would be much better.
The problem is, it's current illegal to install such a mirror in most countries including the US. Innovation illegal... oh well, who needed it anyway.