- spray on, rinse off solutions can't fully cover the paint like a regular wax on, wax off might because there's no guarantee you're covering all sections of the paint. If you are, then you're going through a lot more product.
- 90% of products don't last for their claimed time frame, especially not for a daily driven, parked in the sun car.
You can see at 5:11 when he first rinses it off again that there are sections that still sheet instead of bead (he mentions it right after too). Unfortunately he didn't show how much of the spray bottle he used, but I'd guess between 1/4 to 1/2 of the bottle. Depending on the cost and how long it actually lasts, could be worth it for the ease of use though.
I'm using this 303 sealant on a few of my cars. it works pretty good and is as advertised, spray it on while it's wet and rinse it off and you can see that there's a hydrophobic coating on it. certainly not anything like ceramic or 9h hardness but it is what it is.I would only buy it if it's on sale which they do offer from time to time.