Just a couple advantages of a shell. One, in California it lowers your registration cost because you can remove the commercial lic on the car. Two, the added weight gives it a little smoother ride. Just some of the positives. Yes there are negatives, Viisability backing up, however with that back up camera not an issue for me. It also limits what you can haul around, but the positive in that I dont have every neighbor or relative asking me to move thier refrigerator. It works for me.