I used to put Hardigg cases on the roof ( military,new unused from Uncle Sugar's trash can/auction site).
Even being tall they were a bitch to get down loaded. If you go large enough thats going to be an issue with anything on a rack.
I dont use anything like Jon does-ie daily but have 4 fairly large Hardiggs, 4 2400 Storms, and 2 of the top end Zarges and would agree I like the Zarges best but dont think they could take the abuse a Storm can. Building a shelf spanning the rear wheel wells of the 90 and figure I can get 4 storms underneath. Need to do vehicle dependent while in Colorado and Utah next month. But dont want weight on the rack while doing technical stuff @ Moab. Currently have a Zarges box in the back of the 90 and a Engle on the fenderwell ratchet strapped to the capping. The Zarges isnt full so everything inside gets airborne and roughly treated. Love to see how others pack arrange things. Personally prefer smaller compartmentalized approach to big box, take everything out to get to what you need, hard to keep things clean and dry that way.