You sound just like me (2 years ago). My whole house is ORB. Master bathroom lights and plumbing fixtures are brushed nickel. DH didn't like the idea of ORB on the outside of the bathroom door and brushed nickel on the inside. So I have mixed metals in my bathroom. I asked here and in the decorating forum plus had seen tv shows with mixed metals. Most everyone thought it was fine to mix them. In my bathroom: door, closets and (dark stained) vanity have orb. Light fixtures and plumbing fixtures and tp ring, train rack are brushed nickel. I'm good with it :)
Monica

My entire house has ORB for the hardware and on many of the lighting fixtures. We have chrome plumbing fixtures in every bathroom and kitchen. I think it looks great. I don't know about brushed nickel, but, IMO, polished chrome works with anything. My designer was the one who helped pick out most of the hardware and fixtures and she said this was fine to do.