I have a wells cargo with torsion suspension and like it lot, but I wasn't so sure if it was really that much better than leaf springs.

I saw my answer last night. I was following a Pace trailer which looked to be an 8 x 5 like mine but with leaf spings. It was being towed by a Jeep Wrangler like mine.

Anyways, the trailer must have been empty because that thing was bouncing all over the road. Since we don't put much weight in the trailers (especially a 8 x5 size) I would think the planes would get bounced around quite a bit.