Have been using Instant for a few side projects recently and it has been a phenomenal experience. 10/10, would build with it again. I suspect this is also at least partially true of client-server sync engines in general.
I concur with this. Been using it on my side project that only have a front-end. The "back-end" is 100% InstantDB. Although for me, I found that the permissions part a bit hard to understand, especially when it involves linking to other namespace. Haven't checked them for a while, maybe they've improved on this...