Using these as side panniers and top box on my Honda Transalp Adventure Tourer. Initially was going to go with aluminum top-loading boxes from Happy-Trails but decided on the Pelican 1550's as they were a lot less $ and are a lot tougher than the aluminum boxes.
The side loading Pelicans are easy to load and unload if you use some pannier liner bags. I found some at JC Whitney that fit the 1550 cases perfectly, they are on the site as the Raider ZX014871R removable saddlebag liner.
Pros: Nearly Indestructible, Watertight, Dustproof, Lifetime Warranty
Cons: They're Not Free ; )
This review was written in the old system and had content requirements that are different than reviews written today.