As many have said, the E55 is what I have and really like. I have had the Shad SH50 and that is a fine box as well. I used Phil's rack and attachment kits on both for ease of installation. As far as having a box of these sizes on the rear supports there is NO problem. I had a HEAVY Corbin on mine and it gave me no problems, the E55 is less than half the weight of a Corbin and has a much more forward mounting position.