I use a Vortech rack on my Dragon and strap on a Pelican box I found on E-bay. Works great, keeps everything dry and secure, just have to remember to strap it back on after a break!!
powder keg makes the best one out there. They are more expensive but they will last and keep your stuff dry. I am tired of spending money on bags that don't last. They also make fuel jugs that mount with them. They are even stackable for longer rides. they are all plastic so no tools are going to rub a hole in them. no stitching to come out. They kinda make your sled look like a grocery getter but they serve the purpose. Hands down the best out there in my opinion.