Hopefully it's okay to post this here? Have been playing with sage for a bit now and really like it!
I first tried using version 9 but couldn't get the setup right and didn't quite understand everything. The documentation for 8.5 at the time was really great though and everything made a lot of sense with how the code worked, so I installed that.
But in looking at the differences, I really liked how 9 organizes the src and template directories - so I replaced those bits in 8.5 with, what I believe, was 9 alpha 4 at the time (I don't have any of the blade stuff). I know, I'm probably nuts - but that setup super makes sense to me, it's so easy for me to develop on and has been working great.
I also pulled out bootstrap and replaced it with UIKIt, which I'd been wanting to try (although didn't actually really use with my first website)
Anyway - I might be nuts and have issues trying to get updates, but I really like it. So thank you to the developers and everyone who contributes to it and answers questions here on the forums!!
I did use Beaver Builder's page builder with it, which is maybe bloating it a bit more than it needs - but it makes design/dev so much faster - and the site is still super fast and gets A's for PageSpeed and YSlow - YaY! All thanks to sage: