Do any of them implement the full standard game, including mob AI, the Nether, and the End? It seems like most of them are targeting the easy creative/peaceful mode subset. I'm just a sucker for the full standard game.

I haven't personally used any of them, but I would have to assume at least one of them does since most hosting providers support both BE and Java (though not on the same server, one could dream...)

I personally have a JE server hosted through a company that I play on. I like the ability to have server-side plugins (through Spigot) and being able to back up my world automatically offsite.