I have 3 that have survived and get along with one another and the rest of my tank. They do love to eat. I give em flake, pellet and various frozen meaty bits. I think they like to hunt pods too, I see mine pecking around often. From my little experience they seem to live up to the reputation of being pretty peaceful.
Survival rates I see reported do seem to often indicate a lot of die off. Maybe due to the sources and how they are handled. I think I bought 3, two died, then bought 4 more and 2 of those survived. Honestly I think it had less to do with the environment they went into and more to do with everything leading up to that. Two or 3 of the ones I received looked really rough out the gate and just died within a week.