People saying 16 gig isn't enough room are just plain wrong. For what I use a tablet for, it's more than enough room. All I use it for is music streaming, video streaming, a few games here and there, and web browsing. On my iPad Air 2 I have it fully loaded with the apps and games I use, as well as some music and podcasts and I still have 7 gig free.
As for it being worth the upgrade. At first I said 'no' due to the incredibly annoying screen shaking with audio on, but having gotten used to that I now say 'yes'. Mainly due to the extra memory that has all but rendered the webpage reload issue a thing of the past. The other big difference between the one and the two is the feel of the device. The Air 1 feels incredibly hollow and empty. It's not annoying, but it is very noticeable when you compare the two tablets. The Air 2 is just solid all around.
Not sure if it's worth the price upgrade, but if you can find a good deal, go for it. I got mine on Black Friday from Target and it came with a 140 dollar store credit, which I then used on an Xbox One for the kids, which itself came with another 50 dollar store credit.