I still love my Stoneskin. I'll try to SS everyone at the end of a fight so they have it for the next fight. It gives me a couple seconds to throw out an Aero 3 and do a little dps. It gives a few extra seconds to put Regen and Asylum out before I'm fighting an uphill healing battle. Great for mitigating big hits or stray hits to dps. It's not very mana friendly to spam it but it's awesome to use when you're just standing around during trash pulls or boss fights. It's great when it's used properly and by properly I mean whenever you have extra mp.