Comparison of the iPhone's size at 3.5, 4 and 4.3 inches

I've made a quick mockup to see what a 4.3 inch, 16:9 iPhone 5 would look like and put it next to the iPhone 4S and iPhone 5 for comparison. I would say the size increase from 4 inch to 4.3 inch is similar to that of the iPhone 4S to the iPhone 5. Here's the full image.

What do you think? Which screen size would you prefer and why?

I know it won't happen anytime soon or at all (we all know why). Still I think a benefit of having a 4.3 inch screen would be more keyboard space for faster typing. The question is, would it still be comfortable for use it with one hand?