The different between the classic innovative bottom entry with velcro is that the patented entry on the bottom can automatically give closed beneath the body’s weight and fastens with velcro. While the classic side entrance with a zipper is that the zips enclosed with a whole length as well as a hard duty zipper on a single side of the bottom fabric and the mesh. Actually, either zipper or velcro has benefits. The classic bottom entrance performs great once you are being caught up by a mosquitoes cloud. When you avoid your head down to disclose the bottom entry, the mosquitoes won’t know what you are doing, so they will go away in seconds. However, it depends on your preference whether taking with zipper or velcro.