I had them but they died too soon, despite my established, well planted, well maintained, and peaceful tank. Otos are virtually all wild caught. There are huge losses in the industry where they are not given the care they deserve (tens of thousands die in shops), and in home aquariums. I felt it prudent not to buy more after my failings.
Sadly, this recently discovered species is currently categorized on the IUCN Red List of Threatened Species as “endangered,” largely due to harvesting for the trade.
I agree they are undervalued but personally now see their real value is in the wild. I hope that yours live long lives and even reproduce to continue our learning of how we can adapt captivity to meet their needs.
sources: aquaradise, PracticalFishKeeping