My recommendation is that you decide EXACTLY what you want or need to carry, and then design around that.
Hubster and I were disgusted by the hitch carrier options on the market - nothing would fit our unusual needs, especially where food was concerned (see this thread
). We settled on a design that always allows one of the rear barn doors to open, and if we need both opened, we remove the Yeti cooler and set it on the ground beside the van (tethered by a security lock). Our long, arduous, highly-rewarding hitch carrier custom welding job is described in this blog series
, and here she is - Miss America:
We also carry an inflatable kayak under the leading edge of our vaulted solar panels:
We also added an ATV bag on the roof for more storage:
I use a Telesteps 1400E to access all roof assets:
Anyway, the point being, there are MANY ideas that you can develop for exterior storage. It all depends on what you need to carry, and how much work you are willing to do (or money willing to spend) to get it.