I think a new thread re: sharing experiences with passthroughs is in order. Personally, I use a joye 501 passthrough and like it. Always seems to provide CONSISTENT power. Does anyone have experience about how long these last?? Also, if it uses a battery, then doesn't this battery also have a life expectency equal to the same charge/recharge cycles? If so, what does one gain with a passthrough? Can you leave it plugged into computer, or will battery overcharge??? I trust others have similar questions...they don't come with instructions.