We will return to Florence after completing a cooking class in Tuscany and have a four day time period before we need to be in Torino. We have previously visited northern Italy and the Lake Como region so would like to travel into Switzerland. We are not sure if this detour is doable or if we should look at using train or rental car. Any suggestions for Switzerland destinations or transporation mode?
You definitely have the time - but like Kent was implying, it is a good chunk of travel!
For destinations in Switzerland, I would absolutely recommend Interlaken, and heading up to Gimmelwald, and Grindelwald. You will see Switzerland in all it's glory, and get a nice taste of the German side. There's also things like the Matterhorn, etc., but those are good places to start your research.
Maybe it was just my personal experience - but I really enjoyed the German (eastern) side of Switzerland much more than the French side. Either way, the scenery is beautiful!