I've had both but, we do a lot of night racing here and after , we just hang around so , I sleep in trailer .. too old to sleep in pickup .. I just sold my nice open I had built , tried that again for 3 years
While the open trailer is nice for nostalgia reasons, the enclosed far out weighs those. My enclosed trailer is my garage on wheels. Get home late at night? No worries. No need to unload anything. Just lock it up. Full weekend at the track? Plenty of space in front of the car to throw down a cot, and sleep. I like having my stuff locked up, and secured. Rain delay? Car is inside, and not getting wet.
