I've been twice on the Pibeste. As I was a student in Tarbes, the sport teacher used to organise every year an event "the Pibeste race": we started in Vidalos and someone was waiting at the little cabin on the top with a chronometer. To get the best mark one had to complete it in one hour. I did it with few other people in around 57mn. It was more hillrunning than hiking !
57 minutes ??? I would have failed badly; it took us about 2,5 hours to the summit but we weren´t in a hurry. Did you ever do the traverse to Soum du Prat du Rey ? It looked promising to me but we were too late and there were afternoon clouds around the arete so I abandoned the idea.