Better is subjective, I think Overcoat is a bit better, especially if you like slickness, but self cleaning might go to Premier. Premier is cheaper than Viking so it wins that battle. I haven’t tried VS1.
The thing about the toppers we are discussing is they beat other toppers (like Reload) by lasting about 12 times as long. We really need two topper categories like short term and long term. There is no need to apply a long term topper after every wash like you would apply a short term topper. Applying a long term topper after every wash would be like applying Can Coat after every wash, redundant and wasteful.