When I put my Dinotte 200 on my helmet, I hung the battery pack on the back of the helmet itself, which pretty much balanced the weight fore-to-aft. But, mine was with the AA pack, which only has so-so runtimes (it's part of why I later got a bike with a dynohub), and it still didn't have a taillight. Plus, it took forever to remove, at least compared to all those clip-on lights on the market.

The 360's taillight, and how it effectively has no extra "battery pack", makes it really interesting, IMO.