i have had them in the past, and i will prolly get some more pretty soon. they are great detrital eaters. breaking food down another step. if you have hard to reach areas where detritus builds up than they are good at getting back there and stiring things up a bit.
I have heard that if kept with aggressive fish they can be stressed and poison the tank? is this true? what do they define as aggressive fish? are there some that will work with it, and some that should be avoided? what is the minimum sand depth necessary to keep one?