They're adorable. There's ten of them, and they have a great time winkling around the tank like little packs of teeny, tiny weasels, hoovering up little bits of leftover food and whatever. They don't try to compete for food with the discus, and they're entertaining to watch. They even managed to cope nicely with the eighty-eight degree temperature I still had the tank at when they were introduced (it was still coming down slowly from a meds regimen).
Whether or not they deal with the snails remains to be seen. I THINK i'm seeing fewer tiny snails on the driftwood chunks, but am not yet sure about their effectiveness on that front.