Our dad is an independent contractor and travels around the country to different glass plants. He has a 2006 Tundra which is left outside 24/7. He lets me clean it up when I can because I'm the one interested in sealants and taking care of the paint as best as I can. Sometimes he is home and other times he can be gone for a few months, and if he is close enough, he comes home every so often on the weekends.
My brother owns a 1997 Civic which also is outside 24/7. These two vehicles make for good testers of the different sealants I have tried. I watch for durability and protection. I have tried Zaino, Finish Kare, Duragloss, and Optimum. Zaino did an excellent job and dad said he looked forward to it raining because the rain would wash off the dust that had collected and he said it looked as if the truck had been waxed. I tried Finish Kare next, and was impressed with a few things. I liked how the 2180 sealant really brought back the color and gloss of the single stage paints I used it on. Another thing was how well the Finish Kare kept things from sticking to the paint and especially the wheels. Our dad went out to Washington State in January and came back in August. Before he went, I sprayed the truck wheels with the 146 detailer. When I washed the truck after he came back, I was surprised how easily the grime came off the wheels, so easily in fact, like I had just sealed the wheels the week before, that I thought he had to have had the truck detailed before he came back. Not only did the grime wash off super easy, the wheels were really clean when I got done, nothing stuck to them, not even in the nooks and crannies. I asked dad if he had the truck detailed, and he said he had not done so, and he didn't touch it himself. So, I was impressed with the durability and protection of Finish Kare. I would probably still be using it except I became concerned about the solvent content of the products.
I next tried Duragloss. It seemed to do a decent job, 105 has good durability. I used Aquawax as well. One thing I noticed when I used Aquawax on the Tundra and Civic was that the road grime seemed to stick more. On the Tundra's wheels, the front rims started to have brake dust sticking in the nooks and crannies, something that hadn't happened before. Same thing happened to the Civic, I sprayed Aquaqax on the rims, and after a while I noticed brake dust sticking to parts of the rims that were hard to wash off. And after it had rained, after my dad and brother drove their vehicles, I could see the road grime sticking to the paint after they were dry, especially the Civic's rear bumper.
The last one I tried was Optimum, and it is what I'm staying with now. I used both the car wax and opti-seal on the Tundra and Civic. The durability is really good, equal to if not better then what I have used so far.
My brother drove our dad to the airport the other day, and it was raining when they went. My brother told me later that day that whatever I was doing to the truck to keep it up because as they were driving, dad said how he looked forward to the rain, the truck would be cleaner as a result. I realized he was right, even after driving through the rain, the Tundra and Civic are staying cleaner now.
I know this isn't very scientific, but this are my observations on the different products I have used.