short story is that sponge isnt ready yet and squadron is a pain there are ppl working on packs though give a it a while
exactly what john said. its not possible yet for real server but we have a testserver here: 1.9 Testserver | MineYourMind Community
I remember a post from some official sounding person that basically saying the current setup wasn't able to effectively run 1.9 to standards or such.
Also machines for 1.10 servers must be a lot stronger than these for 1.7.10 ones. 1.9.0-1.10.x aren't as stable as other MC versions. Performance is comparable to 1.7.10 server with 10 players exploring Twilight Forest 24/7.
Agreeing with Arcanuo here, where'd you get that? 1.9/1.10 are designed for multi-threading, which means better performance
Mainly a popular polish MC forum. Many people were claiming that they have really bad performance. I also compared client fps when being on a server (which is completly different thing than TPS, but fps problems makes higher minimum client-side requirements). Got lags, 3 client disconects and a crash on 1.9, and no issues on 1.8 (same server, but multiple versions compatibile). My tests are however old, and made from a 5 years old toaster with main circuits partially metled, so this may not be true for better computers. So source = forums + also one youtuber (who is known to play on a laptop) claimed and shown that he haves performance issues on 1.10.