So the ratings page says that for level 10-Stars and above, Sleepless is pretty useless in both PvP and PvE. Apparently, at such a level, he doesn't even manage to rate a single point (though admittedly, he does rate 3-points at level 5-Stars and 3-points again at level 6-Stars-to-10-Stars).
Anyway, I've got a 6-Star sleepless and an 8-Star Dark Arthindol, but I wanted to be absolutely certain before 'eating' sleepless that he is indeed worthless. So if you're certain, please let me know. Thanks