So my question would be... Does the platinum have too much. Of something ? That I don't need, and like you said, the gold is good enough.
I'd be lying if I said I knew and listed "here is the difference." I started really getting into lifting about 5 years and like most gamblers I kind of have an obsessive compulsive attitude and when I do something, I really do it. So I did a lot of research on supplements and protein. Even the really serious lifters/bodybuilders like 99% of the time bought one protein or the other based on taste. If you Google which protein to buy almost all forums base their reviews on overall taste no matter where you look. Maybe I'm used to it but I really like (ok, really like is a stretch but don't mind the taste) of the ON Whey double choc and regular choc. It's also not the cheapest protein but it's not the most expensive either. Great reviews and a lot of customers use it.
Another poster mentioned Snytha-6 and I tried that once for a couple months because a review said how great it was. I didn't love the taste nor did I notice anything different so I went back to ON Whey.