No rollable loot on Peisteskin is pretty common. I've done like 20+ maps at this point. Best haul I've gotten is 8 Hardened Saps (philo stone item); most of the time the items are worth less than 5k. The aetherial armor that is in the chest occasionally can SB into T4 materia which is kind of nice. Generally I think it's a waste though. I go with two friends and 3 man them sometimes for fun.