I really have no experience with White Labs, as the LHBS in my area mainly carry Wyeast. Never had a dud with Wyeast, but I do carry a cooler in the car and an ice pack when I pick up yeast, and it does go straight into my refrigerator when I get home. I really think that both companies ship good product, but there is no guarantee of the handling in between them and us. If I were to start getting duds, I would bring the packs back to my LHBS and I pretty much know they would replace them or I would go elsewhere.