imho: the best: tunze osmolator, second: elos osmocontroller.
nothing compares to these two, unless its a optical sensor, which i don't know of any other ato that uses this.
I've used everything on the market, jbj, avast (currently own but using on waste container), hydor smart, older elos with float valve, diy, etc...
nothing comes close. but for what we need, i think they work fine.
only reason why i sold my tunze is because i'm going to use the same type of sensor on my Profilux for ago, which i think will be just as good.