I’ve used water wetter and it is good in my opinion. As people have said though, check everything is working as it should be, but looking at the temps you are seeing, it sounds like everything is working as intended.
any brand better than others?
I think that the air-con cars run hotter because of the condensor reducing air-flow to the radiator.
This seller got mine to me next day if anyone is interested.
Just be aware water wetter will also find any miniscule issue with gaskets, joints, bonds, etc in the system so if you use it keep an eye out for new leaks.