All very minor things. Absolutely nothing significant lost for the gain in design and weight, in my opinion.
I actually think a bigger loss is the lack of RAW photos (assuming I have read that right on Apple’s website).
USB2 sounds bad on paper but how many folk really transfer masses of data to their iPhone via the cable? I know I haven’t done so in years.
Yeah... I was all set to purchase a 17 Air. But the loss of RAW format when making photos will keep me using my 16PM for another year.
Using Lightroom for all of my image processing, not having RAW available is too big of an issue for me.