Okay, so Switzerland, France and Italy are no go... I wouldn't wear a rep to Malaysia, Indonesia abd some parts of China for other reasons
To second what Wiz tells you, guys, I live in France (very close to the border with Switzerland), travel quite a lot, sometimes with reps, sometimes with gens, always with a watch which "face value" is in excess of 2000€. In the beginning, I was always with the gens, and sometimes carrying some certificate... Stupid me!!!
Not a single time has someone stopped to even look at my watch suspiciously. I've had some comments (in Geneva Airport, CH, and going to France, of all things !) from an official guy when screening me... like "nice watch sir" and me "thanks!" That's all!
Honestly, they don't care a lot (whatever the law says, it's more important catching something that my be used as a weapon in the air plane than any counterfeit items) and if you look "the part" you'll never have any problems (and when I say look the part, it's not look "blingy", mind, I'm mostly wearing jeans and a shirt... it's more in the demeanour, attitude, etc.)