I got it today! 
I remember watching a video about it on Youtube some time ago and wanting to try it, but then proceeded to forget about it... until I saw your post today and decided to give it a try, lol.
Here's my first attempt with it:
Decided to try with watercolors, because that's one of the media I'm the most familiar with.
The good so far:
- The way brushes behave is indeed similar to real life ones. I couldn't help but laugh when at some point I was working a little too fast with my Apple Pencil and a tiny dot of watercolor paint appeared somewhere near the area I was painting, just like it would happen with actual watercolors when you accidentally end up spraying colors over your artwork if you're not careful XD
- Textures look pretty realistic, especially when you zoom in. One of my biggest issues with many art programs that supposedly simulate traditional techniques is how textures are more often than not just a bunch of repeated patterns, while this doesn't look to be the case.
- The fact that pictures will look like they were taken in an actual art studio is so damn cool!
Love that they have multiple options for the final picture, too!
The meh so far:
- Brush sizes are... weird? Looks like the "biggest" brush size isn't that big at all, at least for watercolors. Turns out that, to get bigger strokes, you need to be pretty heavy handed, which... yes, is what happens with watercolors too, but like... bigger watercolor brushes do exist in real life and I can't understand for the life of me why they'd make sizes so limited ._.
- No mixed media. As a mixed media artist, I can't help but wonder... WHY? D:
- As much as I love the "artist studio picture" mode, the software could really use a regular image export mode in high resolution. The images you can export so far are pretty low res and only really good for social media, which makes the program kinda useless if you want to use it for more serious purposes. (Note: a little workaround could be taking a screenshot of your canvas on the iPad, then importing it into Photoshop and resizing it, but still... not as good as being able to export an actual 300 dpi pic).
All in all: lovely program, but a bit overpriced for the features it currently offers. My biggest gripe with it so far is the impossibility to export high res images, 'cos otherwise I could see myself using it A LOT for my art ;__; EDIT: waaaaait, looks like there IS a way to export pictures without the scenery thing! You have to do it from the main menu rather than from the canvas itself. Not sure about the resolution, but hey, at least there IS an option to export your drawing that isn't taking a screenshot from the app, which is good ^___^
