I have the 2017 12.9 (it is my work machine) and just bought the 11 as a companion (replacing an Air 2). I just stopped by the Apple Store because I’m having delivery issues with my accessories, and I got to check out the 12.9. I’m super impressed. The new 12.9 fits in my purse (I did it in front of the sales lady), and yeah, is just night and day more convenient than the 2017 12.9–and I’m saying that as someone who loves my 12.9.
I still think I made the right call for my particular situation... I don’t need two 12.9s. But if I were only going to have one iPad (and no laptop, like me), I would go 12.9.
That said, this post is the first thing I’ve typed on my new 11, and I’m really happy with it. The keyboard feels comfortable, it’s super light, and I can definitely see myself traveling with just this iPad. It would not be a hardship to do my online teaching sessions on it, with this screen size. I think my 12.9 will be staying home— it will still get tons of use there.