On my last caravan i paid extra for a pneumatic wheel, i found it a great disappointment, and wouldn't have another, although it never lost air, the possibility of a flat tyre was always present. With the larger diameter ground clearance was a problem, i did take it of for towing a couple of times, but in the end it was too much hassle, we didn't have a mover on that van so we fitted the pneumatic wheel to aid in pushing the van, it made no noticeable difference.
All you need id a wide solid wheel. As i have with my present van.