We added a topper on our slide. It wasnt that big a deal prior to climb up on the roof, well 10 years ago-reaching out over the edge-trying to sweep the debris off, or sweeping with towel to get most of the water off, or inside with a towel when raining. Never had issue with puddling or wind-ours is 116" fabric on a 120" tube but it only protrudes less than ~18". 
As nice as it is to not have to climb up there to clean or dry, we added the slide out topper due to noise. Our slide roof is hard, its covered in EPDM but anything that lands on it is LOUD. Rain just drums-water dripping off trees louder than some one knocking on the door. The topper solved this-not getting on roof just a bonus.