That's silly - the 5S can be sold for the most and you'd likely be able to buy one of the others + pocket some cash
Not sure what is subpar about the camera - maybe not as good as the beastly shooters in the high-end Lumias, but it beats everything else in general.
The display is absolutely fine for a 4" display. Now perhaps that's too small for you (it's beginning to be for me as well), but as far as color reproduction and quality go its top of the line.
The A7 was the fastest processor on the market until this year's crop of devices. So comparing a 2013 phone to those that have come out in 2014 is a little bit unfair. Speed/Power wise, it's more powerful than apps can take advantage of.
iOS 7 is great from a feature perspective and comparing it to iOS 3 is hyperbole....I would've expected better from you. I get that people are turned off by the design (though I happen to like it), subjective portions can't really be argued.
Keyboard may be small, but the auto correct is far better than my Nexus 5 TBH. If the Google keyboard didn't have swype typing, I'd hate it. I'm far more accurate when typing normally on my 5S than the Nexus 5.
Anyhow, I'm glad people are taking notice of the 6/iOS 8. Definitely the biggest release to date IMO - they say it every year, but this year I think it'll be true. I haven't been more excited about an iPhone release than I am about this one.