... which is not to say that you can't recognize Swiss people speaking standard German from a mile away - and not just because of the accent, but also because of vocabulary and diction.

'Swiss German' and consequently 'Swiss standard German' contains lots of French words, like 'billet' for ticket, 'poulet' for chicken, or 'velo' for bike, which Swiss people will use in standard German. In Germany or Austria these terms will produce blank stares - and very often Swiss people are not familiar with the "proper" German expression. Also, Swiss German tends to be simpler grammatically, and consequently Swiss people tend not to use the genitive, for example. While this is perfectly fine in spoken language, it sounds unrefined in written language - which is why it is easy to recognize something that has been written by someone Swiss. Add to all this the fact that Swiss people tend to speak a lot more slowly, and you're set for having communication barriers. Once I witnessed a elderly Swiss lady trying to buy a waffle at a Christmas market in southern Germany - the woman selling asked in standard language and speed whether she wanted powdered sugar or apple sauce on the waffle for an extra 50 cents - it took another 2 minutes of explaining until the Swiss lady finally recovered from this expression -> and caught on.

A few Swiss people have actually told me that they do not like to speak standard German, and that they'd much rather speak English with someone who doesn't speak "Swiss"...