I went with the L2D Premium for the reasons cited above. Also, if you ever run out of charge during a ride and for some reason don't have spares, you can buy AA batteries just about anywhere. In addition, AA batteries are very light and compact, so spares are easy to carry in a seatbag. My digital camera and some taillights run on AA batteries, as well, so I would rather just keep it consistent. My other taillights use AAA batteries, but my charger can handle both AA and AAA batteries.