So, having had the iPad Pro 10.5 for a week, I think it's the best Apple device I've ever owned. It hits the sweet spot in terms of size and it's blisteringly fast. I'm typing this post now with the Smart Keyboard I bought, and it feels surprisingly great! In the end I decided against the Logitech Slim Combo, as while it does everything (full case rather than just protecting the front, holder for the pencil, backlit keyboard), from the reviews it sounds like it does none of them particularly well, unfortunately!
In terms of apps, I've been amazed by a couple. Affinity Photo is well out of my skill range really, but even a complete noob like me can whizz everything around and see the power of the software. Lumafusion, though, is a revelation. It's a video editor, designed to be the first 'Pro' level one on iOS. It's pretty astounding - the app laughs at manipulating multiple 4K video tracks, and since it's a pain to be in front of my Mac compared to carrying my iPad around with me, the prospect of doing some actual serious video editing without needing to use Final Cut Pro X is strawberry floating excellent. Lumafusion is very user-friendly and a big set of video tutorials has recently gone up. The roadmap for development is very promising, too.
As an amateur electronic music noodler, it's lovely to report that the Pro can load a bazillion apps into Audiobus or AUM without even starting to fall over.
I've barely used my Apple Pencil yet! Need to dive into some tutorials for Procreate, though I am the world's worst artist.
Anyway, if you're on the fence, buy this thing. It's fabulous.