A lot of people appreciate the modern flat design as fresh and clean. I’m not one of them. I don’t care that much if a knob is red, white or blue, but I do want a knob to look like a knob (and not a flat colored circle).
It would be cool if Vital Skins in the future could handle more complex design elements than just color.
(Please note that I’m not trying to start a debate whether flat or skeuomorphic design is “best”; that’s a pointless debate since it’s just a matter of personal taste).