WOW! That is impressive stuff... Do you have any idea what caused the dip in pace/power? Lack of food, general tiredness, lack of high mileage training volume??? Good to see you managed to ride through it though!
I was tempted to do the Welsh 12hr, which was on last weekend... But decided it was too close to Three Peaks and I wasn't prepared enough for it, not enough long hard rides. Maybe next year. Very few women do it...