I feel the loot lockout is going to be something that, while statistically minor, will definitely exert a disproportional amount of negative ill will toward the game. For example, studies show that 1/3 of guys hack in Diablo 1, but I'm sure if you asked anyone who actually played Diablo 1, they'd tell you that clearly everyone on BNet hacks. Like hacks, having someone leaving after they got their loot is just a very irriating experience that even if it only happened 1% of the time, you'll still definitely remember it when it happens to you.