This whole thing makes my head spin...
I can only assume that one wouldn't want any sort of protective case because they feel the product is inherently beautiful or (and I'm not saying this is true for this particular scenario) they're shallow enough to want to display their goods for all the world to see.
However, assuming neither the former, nor later is currently true anymore, then why not put a damn case on it and call it a day? Especially if it kills multiple birds with one stone?
I know everyone is entitled to their own feelings, but this is some weirdly circular thinking.
Personally, I don't really care what they look like and they've all gone into cases (I'm partial to BodyGloves), so I can't rank them. They are an expensive, fragile tool and should be treated as such. Screen size on the regular 6 is perfect for me, extra real estate is always appreciated for older eyes. Although I will say it's about as big as I can go for comfortable one-handed operation.