You know, my shower faucet is the same way, and while it wasn't the top of the line model, it isn't the bottom of the line model, either! I've also found that the spots don't go away with cleaning. It seems to be permanently tarnished, which is very frustrating! For now, we just make sure to completely dry the faucet after each shower (well, by we I really mean I do it, to the point of running into the bathroom after DH or DD take a shower to dry it off for them, lol!). I recently read that WD-40 will remove the spots and help protect it from further spots, but I haven't gotten around to trying it yet. I'm a bit worried it might permanently discolor the faucet, but honestly, I don't think I have anything to lose at this point.

Have you tried white vinegar followed by water and towel dry?

I have a brushed nickel bathroom faucet and it must be dried after each use or else it spots. If I spray a cleaner on it, I must then follow with water and towel dry or else it spots.