Owning both a open and enclosed trailer I would say both have there uses.
The open trailer is great for "emergency car purchases " that have to be done quick and tend to involve tight drive ways and backing into a blind jack. And are great for local one day events.
The enclosed trailer is great for putting everything into one box before, during, and after an event.
Adding lights, fans, radio, beding can all be put inside and make a nice place to hang out.
Dry place for cars, gear, and people.
Overhead protection from hail.
Finally, there is nothing like pulling into the driveway after a long race weekend and driving 4+ hour to get home and not having to unload anything. Just park it, set the brake and take a shower , relax, and get ready for Monday.
The cons of the open trailer are many but a few quick ones, poor resale value. Lack of security , I have loss many an air tank, jack, tools over the years.
Have you ever tried loading a car with race tires onto a wet metal/wooden deck trailer?
No fun, at all!
Straps will degrade due to UV if you have to leave the car on the trailer. And having to unload everything after a long weekend and a long drive home.
The cons of an enclosed trailer are in my opinion worth it. Up front cost are higher but the enclosed trailer have good resale value, the size and weight, tow vehicle requirements are higher.
I dont really see an storage issue as like trailers will require almost the same amount of space.
Paul B