We don't have them on our current, new Bighorn 3010, but did on our previous Komfort. I liked having the cover, despite having some sag in an older installation. I want to get at least one put on for our kitchen slide to shade/cool the refer area and keep debris off (such as autumn leaves while we have it parked) but I'll have to wait until the piggy bank fills a little more. One strong recommendation, though, if you choose to add a topper, be sure that the fabric is hemmed or otherwise strengthened on the edges to keep the wind from fraying those edges while travelling, particularly the leading edge. I replaced the fabric on our previous rig's slide topper with an inexpensive topper fabric and it frayed after a year and about 4000 miles of travel. When I do add a topper(s) to our new unit, I will be leaning toward a cover of some sort for the rolled-up topper, even if it is only a tougher fabric for the last roll of the topper -- much like our main awning appears to have.