It appears you're going to be interfacing with the watch quite a bit through the digital crown, tapping gestures etc. The stainless steel versions look shiny compared with the aluminum sport watch, it seems to me the stainless versions would be susceptible to smudges from the constant handling of them, the same would appear to be a possible issue with the gold versions as well. If someone is purchasing it as a fashion accessory maybe there will need to be an accessory with a microfiber cloth attached to keep it constantly polished...