It’s entirely about your UI preferences, really. Most third party apps had feature parity, and the features they didn’t have were more niche. You could find something each of them did especially well, but the vast majority of features an average user could want were present in all of them. Boost was my preference for a more graphical experience, and RIF was my default for its simplicity.

Sync has an extremely vocal fanclub because its dev is very involved with the userbase directly, but it’s really not much different from the other graphical ones save for its MaterialYou integration, if that’s something you care about. It’s as respectable an app as the others.

If they had longer than 10 days to live I’d suggest trying each one to see which fits your preference…but…