I have both opticoat gloss coat and polish angel glasscoat cosmic...
Will they reduce swirls? maybe.
What does it actually do? Its like a super ultra sealant, really just protects from dirt, it will NOT save you from a rock chip or the swirlomatic from the dealers/bs car wash.
it requires just as much maintenance as not having a coating, so YMMV.
Not all coatings are created equal... Im going to put the Polish Angel Cosmic on my fiesta (even tho some fucktard already messed up my rear bumper... I touched it up and polished it out.. looks half decent)... Opt on a E350, and whatever else I might try in the future on some other cars.
Polish Angel
Opticoat Glosscoat
CQuartz
Gtechniq
and maybe 1 or 2 more "name" brands are reliable... these are the better/harder/more swirl resistant coatings around, I cant speak for anything else as I never even seen them in person.