I had the hotshot for a while, liked its small size, but it was not bright enough, so I replaced it with
this one. It's much brighter. The main complaint about this is it can't be mounted to the rear rack (the manufacturer claims it can, but the tinny short screw is a joke--its length is barely the thickness of my rack mounting tab).
Amazon: "The Brightest Taillight on the Planet producing over 60 lumens" You could probably call Amazon customer service and get a freebee.