I just went through this while redoing two bathrooms. I started out with satin nickel on everything - plumbing, light and handles - but then realized that I much prefer ORB for lights and handles for my med stained QS oak mirror trim and cabs. I asked a designer friend if I was delusional for wanting to mix these on top of brass door knobs. Her reply was that if I was, she was, too, because she's designing a bathroom with exactly those finishes down to the brass door knobs. I paged through my stack of shelter mags and spotted a number of bathrooms and kitchens that mix it up with hardware finishes. It looks good because everything is in the same style. In other words, you can mix satin nickel with ORB as long as you don't combine a modern faucet in satin nickel with Old World cab handles in ORB. btw, pay attention to the ORB finishes of your choices because that finish isn't consistent from manufacturer to manufacturer. Some are a dark brown matte while others have a dark coppery color showing through where wear might occur. I think mixing different ORB finishes would be more noticeable than mixing ORB and satin nickel.

GW: I researched that question awhile back when the ORB lighting I found that I loved, didn't match my nickel cabinet hardware. The vote seemed swayed to the "no, it doesn't have to match". I tried like heck to find nickel looking lighting, but most of it was too cool and modern looking, and I found myself drawn to less modern looking lighting selections. I ran with it, and heck, I didn't even stick with the 'style' of lighting that would've been more in keeping with my other kitchen selections. Most of my kitchen choices are 'mission' style, and my lighting selection is, well I don't know what it is... it's MY style. How 'bout that? I found what I liked and went with it. I've often wondered about the mixing to styles, but I love my lights, so I just call my style "eclectic". Yeah, that's it, eclectic. :)

IMO it really depends upon individual situations. Proximity weighs in, too. Of course, all the same finishes is fine; but that does not mean mixing isn't to be done, just that it needs to be done thoughtfully. A mix can draw attention to what you want to be focal points and can make a room be more interesting visually. In our guest bath, all of the finishes are brushed nickel, except the TP holder. But the TP holder is attached to the side of a dark wood vanity, and I did not want to draw attention to it. The antique bronze blended in perfectly, yet does not look out of place because it is visually an extension of the vanity. Along those lines, shower curtain rods, shower door handles and toilet levers are often not a design feature you want to accent, so I would use what would make them visually less noticeable. Ceiling lighting and sconces generally are the same finish, but I believe you can successful pull off an outstanding antique bronze chandelier, for example, by having utilitarian sconces and faucet fixtures in a nickel finish. Items on the same impact level, such as faucets and towel bars, I would usually try to keep the same finish. If the faucets are the focal, they could be one finish and the balance of the other items in the room be something else. As for proximity, I believe all the finishes inside the shower can match, but be different than the finishes in other areas of the room, IF there is a reason/point of doing so. A shower head in one finish and the shower knobs in another would be trickier to pull off but may work if the finish of the knobs blended with the tile so the shower head becomes a focal point. Some finishes mix better than others. And the design style of the features in the mix matter. As does the backdrop, as mentioned above.

I prefer to use the same metal cabinet/door hardware throughout the house. Most are the same style, but all are polished brass in my house. It unifies the house. And your hardware will never distract the eye from a gorgeous view! It would draw the eye so much that a big pike of dog poop. In the middle of the floor would be unnoticed and stepped in!