I'm on the fence now. It only having 2GB of RAM makes a mockery of the 'Pro' name.
So my main choice now revolves around other factors. I current have a 32GB iPad 3, and I think I can survive going forward with that storage size, so in that respect the £60 difference isn't too bad. The single core performance of the Pro is also significantly improved, performing ~50% better on Geekbench compared to the Air 2, additionally multi-core performance is higher although not so important given no apps truly take advantage
However I can't help but be concerned about getting shafted by Apple with future iOS updates. I got burned badly by being a Day 1 iPad 3 buyer, as since iOS 7 it's been pretty much inoperable, haven't used it consistently for probably 6-8 months now because it's so painful to use. Some of that is down to the processor being underpowered, which obviously isn't an issue with the Pro. My concern comes in whether the 2GB of RAM will be adequate in years to come.
Does anyone have a iPad Air 1, if so, how does iOS 9 perform on that? The air 1 only has 1GB RAM, so should be a good indicator of what could be the Pro's near future.
I'll think about it over the next day and decide when I wake up on Thursday