Our experience when we were stopped at the Swiss border led us to believe they were only interested in whether we had the baffle in our aftermarket exhausts or not.
I stood back while the fella peered down into my pipe (ahem!) with his shiny torch then looked at me with an approving eye..... thank god I'd left both DB killers in my Blue Flame, I was good to go.
My mate wasn't so lucky, he'd had the mistaken believe that his BMW 1200GS sounded sooo much better without one he'd left it back home in Blighty...... the copper had a field day looking down into the empty cavern inside his Akropovic and hauled him into his office. 40 mins later my buddy appeared having had the riot act read to him...... 400CHF fine threatened if he ever entered Switzerland again without one. They photocopied every document he had and made it perfectly clear he was a very 'bad man'.
My mate now doesn't do Switzerland but I wouldn't hold it against them..... still the most amazing country to ride a bike in.