I don't have experience with Maxxis, but I have been riding Conti Race King as my rear tire for years. I would suggest you to pick Protection version and don't even try with Racesport. Racesport surely is lighter, but it's harder to set tubeless, not impossible but still far from super easy, and what's more important, it's super fragile. Something like Thunder Burt. I loved Thunder Burt, but for me it was pretty much one blown tire a week, which is just too much hassle.
Conti Race King Protection is super easy to set. Put it on, and most of time, you don't even need sealant to work. But it's not entirely in Thunder Burt range when it comes to rolling resistance. It rolls really nice, has good enough grip for pretty much anything for rear tire, even though from 2018 on, I have feeling it has worse grip in wet then it had before, but no matter what, it doesn't roll as good as Thunder Burt. But contrary to Thunder Burts and one failure a week, I had maybe 2 or 3 problems with Race King in all those years I was running it (almost 10 years). This year I'm back to Schwalbe also for rear (for front I'm always on Schwalbe, as I really hate how Conti's X-king was), and in 3 months I had 3 punctures of Racing Ralph already, so most likely I'm back on Conti next season... or maybe it's time to try Maxxis?