Not saying anything wrong with the 4, but the weight and speed are two attributes of the iPhone5 that you only appreciate when you've spent a lot of time with it and try to go back.
You know, like when you upgrade something, and don't notice too much difference, but if you ever go back to your old one, THEN you notice it.
For me, the iPhone 5 felt light and 'cheap' when just inspecting it, but after use, it does have certain elegance to it. It's light, but not really that 'cheap' feeling once you get used to it. It has a nice heft.
I don't have a nice fast iOS device (iPhone 3G, iPad 1), so a modern iPhone was bound to feel substantially better for me.
Good post. I can respect that.