I've used a couple of Hepco and Becker ones including a Gobi, which doesn't take any of my helmets, but is double lined so effectively insulated, has rails on top to tie down kit onto and performs well. To get a bit more space I've also got the TC50, which easily takes a full face helmet, and to which I've added the H & B luggage rack to.Not double skinned so lighter, and less stronger that the Gobi I'd guess. One benefit of the Gobi is that you can have the locks unlocked, and latch the lid, so it's easier to get stuff in / out when on the road, whereas the TC50 is either unlocked and open, or locked and closed, which may be a bit more secure on the road.