My gf has kept them a few times over the last year with varying results. I've tried keeping them in a shrimp tank, but they never live. They're super sensitive to ammonia. She did get several to berry up and produce offspring, but that was in their own container with daily RO water changes. At once point she had 10+ in a container and they all died off one night due to what I think was an ammonia spike. They're cool, but get kinda creepy looking when they get older.
Here are a couple pictures of the ones she had last:
Maybe when we get moved into the new place we'll try raising them again. We still have a bunch of sand that has eggs in it. If you want to raise them in an established tank, make sure you don't dump the egg packet in an already established aquarium. I'm pretty sure that is where my limpets, daphnias and hydra's came from.