A mirrored splashback visually expands the space, adds light and life, and looks stylish in an all-white kitchen. But you have to know what you're dealing with. You need to use toughened glass and the toughening process does give the mirror a slight smoky cast. The cooktop must be set as far forward on the bench as possible. Mirror reflects everything in front of it, so it's not a good choice for the untidy. Having said that, I have a gas cooktop with mirrored splashback, and I find the mirror easier to clean than stainless steel. A powerful overhead exhaust fan will minimise smears. Mirror reflects everything in front of it, so it's not a good choice for the seriously untidy.