We have enough time in our schedule. Is Geneva worth a couple of nights or should we just take the train straight through to Chamonix?
If you do decide to stay over in Geneva, taking a bus to Chamonix will be quicker than the train.
It depends on your interests. I come for the mountains and have had my fill of big cities within 2 hours. You can easily spend 4 days in the Chamonix area. Annecy may be another option for a day or so on the way to Chamonix.
I stayed in Chamonix with my brother and his wife for 3 nights a few weeks ago. From there, they had to go to Geneva and go on to Amsterdam and then the U.S. They ended up staying for one night, I stayed for two and from Geneva I went on to Lauterbrunnen from there. I'm glad that I stayed two nights, the first day, we walked a lot on both sides of the lake so that we could see the fountain etc. You can take a ferry boat across the lake if you want, or take a lake cruise, etc. They left the following day, and I walked to St. Peter's Cathedral (you can walk up one of the towers for a view), and then explored the Old Town. From there, I walked all the way to the Botanical Garden. You could spend an entire afternoon at the Botanical Garden (which are free by the way)....they're amazingly beautiful with over 12,000 plans spread over 60+ acres. From there you could walk over and get a tour of the United Nations building.
I don't think you'd regret spending two days there if. you have the time, Sandy