I didn't see any towing experiences reviews after the questions were asked on page 1, so here's mine...
I ordered my top in May or June of last year, for the main purpose of having a cover while towing. Marshall said it wasn't designed for towing and he wasn't sure how it would do. So I gave it a shot. In July I made a trip 5 hrs one way, all 55+ mph roads. The first 5 hr leg was fine except for massive ballooning of the top. Half way through the return 5 hrs I noticed that the material was tearing away at the 2 rear grommets, as well as the 2 mid grommets. By time I got home the stitching at the back upper corners had come completely undone to where I was left with ~8" long vents. I took the top to a local sail shop where I had them remove all of the grommets and reinforce the locations with heavier nylon webbing on both sides, then reset with new heavier grommets. I'm also now dealing with the binding completely fraying apart between the forward and middle grommets on both sides.
Now to combat the ballooning, I have to use ratchet straps over the front and rear cargo area. Also I've found that only all rubber type bungees work, because the fabric coated ones stretch too much and eventually fail from the constant shortening and lengthening from the top flapping at highway speeds. Overall I really like the top, but it's not strong enough for longer towing trips without more time and money on the buyers end to reinforce it.
I'm considering now getting a new one to start with a clean slate for reinforcing it.