FWIW, I've found both to be excellent polishes.
Brunswick appears to have slightly more abrasives in it. Brunswick used to apply it over 400 grit (US/CAMI grade) and got a very high gloss finish.
Personally, in most cases, I'd rather use the less abrasive polish so that I get where I want in gradual increments more easily. You can do the same with the more abrasive polish; you just need to exercise more caution.