I stayed at Mann Lake as an alternative to camping on the Alvord Desert. We initially were sleeping on the desert until it started raining hard in the middle of the night and we evacuated to avoid getting stuck.
Luckily, even in the middle of the night, there were plenty of spots and everything was pretty peaceful. We ended up staying for two nights.
Just know that Mann Lake is part of an open range so we woke up to baby cows shaking our car (which we didn't mind). All around good place to stay (though less exciting than camping on the playa) if you're going to the Alvord Desert.