The campers are appealing to me because of the smaller parcels and lower prims, as well as all the beautiful landscaping. There is more space between the parcels and it is less likely people will stuff their land with high prim items full of scripts to lag out the region.
There are usually 15-20 houses or houseboats in a region or 20-24 campers, I find campers to be the best deal if you want to avoid lag!
When land is abandoned without items being removed, everything is returned to the owner(s) as coalesced objects. These can be rezzed at a sandbox to find individual items.