Is it worth it to buy one of these? I have two Wii motes, I use one fairly often, and the other not as much... only if I have a friend or guest over. I don't go through my batteries that quick, and I figure a pack of batteries isn't really that much... but would it be more cost efficient if I got a charging stattion? If so, which brand is the best? Or should I just get one of those cheap $10-15 battery chargers, without the wii-mote docks?