Just thought I should offer this so I don't get jumped by devoted self darkening hood users.
My bad experiences with the self darkening hoods were with two different ones, both were solar rechargable. They were company owned tools and apparently not charged regularly by the guys who were supposed to do it. Both times the lens went clear while I was TIG welding. After the second time I vowed not to use them again. If I was to buy one for myself I'm sure I would keep the battery charged properly and wouldn't have any problems. Owning one is just not a high priority item because I'm so used to my old hood with the fixed lens.