Hi John,
I exchanged my license about a month ago. You need to have an eye test it costs chf 20, takes 20 mins and the optician will complete the form and have you sign it.
I then went to Bureau des Autos with, the form from the optician, my original license, new standard passport colour photos and CHF 140 (i think), when you enter go to reception, the person there spoke perfect English, checks your documents and then tells you were to line up to get your license. Extremely efficient and helpful.
I queued for about 30 mins and then went to the desk, had documents rechecked and photos scanned and answered questions in extremely basic French as this lady spoke no English. Again no hassle no stress very helpful people there. She then told me to wait at another area and less that 10 mins later they called my name and I paid and collected my license on the spot, no hassle no issues.
I work for a UN org in Geneva and although you are exempt from having to obtain a Swiss license, my national driving license was about to expire and I had no chance to go home and renew it. I just explained that and they happily exchanged it for me. The great thing is now my Swiss license never expires (which I think is genius). When you read the form (from the website or optician) it tells you the countries Switzerland has an agreement with for license exchange, USA is on it (just FYI).
It was a pain free process for me, I hope it's that way for you too.
One last thing, I wouldn't leave it till 4pm (when the office closes) to go, as the queue was very long and they lock the front door and you cannot get in, people exit through a side door.
Bon Dimanche!