Is the Retina worth £60 extra over the old one?
Its not just the screen though, you get the A7 chip instead of the A5. There is a big difference!
Is the Retina worth £60 extra over the old one?
In a heartbeat. Anyone buying the original now needs their head examined.
Maybe those that buy the Air think they are getting more screen real estate (they aren't), or that it's more powerful (for all intents and purposes, it's not)?
Anyone have any theories?
As far as I can tell, the difference is that the Mini is hard on some people's eyes...
You are right about the mini retina screen being inferior to the air screen, but I doubt 95% of the population cares about that. It's still a "pretty good" screen.No, the difference is that the mini has a significantly reduced colour gamut compared to the Air. Many people may not notice or care but the difference is there. Apple are sweeping this under the carpet as a non-issue and still claiming that the Mini is identical to the Air in all but size, which is blatantly false.
You are right about the mini retina screen being inferior to the air screen, but I doubt 95% of the population cares about that. It's still a "pretty good" screen.
Physically bigger, but you can't fit any more on it. Like taking a photocopy of something small and enlarging it. Yes, it's physically bigger, but how does that help?
Plus heavier, harder to hold, takes up more room (e.g. won't fit in even the biggest pocket).
I guess this comment sums it all up...by that logic there is no benefit of an ipad over an iphone?
The mini retina and the air have EXACTLY the same number of pixels, so they display the exact same amount of information on screen. The air has larger pixels, that is the only difference.

I caved and bought a smart cover for my old mini. I can't believe I didn't get it sooner - I could have used it so much.
It is just the Apple one but its really nice being able to stand it up properly instead of just holding all the time, great when watching a video.