We didn't have our TT too long before I came to the conclusion that it was a pain to have to worry about cleaning off the slideout everytime before retracting it, so I had a slide topper installed. The downside of the slide topper can be some flapping noise in very windy conditions, and some puddling of water. The water issue is very easy to solve...simply retract the slide to remove the water. The wind flapping isn't frequent enough in our travels to be a problem. And, a slide topper does mean another awning to clean...so it boils down to whether you camp in areas where you will get debris on the top of the slide and whether you want to possibly have a little extra work everytime you retract the slide...or a little extra cleaning/maintainance by having a slide topper...as well as the extra expense of one!