I have the soft rear, but no zip open window on it. Seems to seal and work fairly well, I will add the zipper to it so it can be rolled up though. Be nice to have flow through sometimes. My goal is to have it so I can completely seal it up in inclement weather, and roll it all back to open it all up, ie: flip up windshield, roll up back window, roll back side curtains, all stays mounted on machine and ready to use if needed. I do like the hard rear windows, but they would be best with maybe a slider modded into them?
The only drawback on the soft stuff I have found is attachment. They use velcro stick on, and sewn on straps to attach. The sticky velcro doesn't adhere well after time, and especially if it's on any of the plastic areas. I solved this by converting all the soft stuff to snaps instead of velcro. Found some nice black snap sets on amazon.