Just wanted to do a quick update on this topper. We loaded up the family and dog over the weekend for a family get together and did about 750 miles over two days. The top performed really well. No flapping at all on a very windy day going a sustained 82 mph on the freeway. The dog did great in her kennel both traveling and overnight. Then coming home yesterday we went through lots of heavy rain most of the way and we didn't get a drop in the bed so everything stayed nice and dry.
Now that we've lived with this thing for about 3 months I can say it has two objective cons - cargo security and somewhat hampered visibility. Beyond those two issues it's been great. It's out of the way and basically looks like a rolled up tonneau cover most of the time, but when you need it you can have it up in 5 minutes and it works really well and gives you a lot of weather protected storage.
It definitely has some compromises compared to a traditional hard sided topper, but they're worth it for my purposes.