So far, the Pro is quite limited in its capabilities software-wise. You don't have a pagefile which is the reason why professional app suites are staying away from iOS (iPadOS, if you want to call it different) and put baby versions of their applications on the App Store.I don‘t think the air is a very good deal. The entry level 11 pro offers a lot more value for the $200 more. Double the RAM, double the storage, almost double the performance, promotion, quad speakers, faster port, center stage and a slightly larger screen for the same size. Even just the RAM, storage, promotion and speakers more than justify the 25% higher price. I am not even mentioning face id as some people don‘t like it.
And I don’t think they are getting rid of 13in MacBooks any time soon
If we had a pagefile, apps would be exempt from crashing caused by memory allocation (imagine a device having 5 GB of RAM and the OS taking 3, and your app using 2 - as soon as it uses 2.1 GB, your app crashes on iOS while it will persist on any desktop OS because the excess memory is temporarily put on the SSD) and we would receive true productivity capabilities. Until then, we live and work at the grace of said third-party's autosave implementations and all that RAM doesn't mean much.
Quad speakers on a single (and relatively small) device doesn't mean much, it's still all coming from the relatively same direction, and the faster port is negligible considering you don't get to use it as a second scream on a system level (only "approved" apps which is to little, too slow).
I would probably still choose the Pro over the Air just for the hope of, some day, being able to actually have a multitasking implementation which matches the efficiency of macOS multitasking, but those are still dreams and I wouldn't recommend others to cash in on hope.
Until then, I'm hoping on this year's mini to match the Air design and get it with an Apple-provided keyboard, netting me the best current productivity scale iOS has to offer in the smallest iPad form factor.