7 days in Austria, Base ourselves in Vienna or Salzburg?

Vienna and Salzburg are ~200 miles apart, one way, so that would be 400 miles per day to do one as a day-trip from the other. Whether by train or driving (you didn't say which), it's unavoidably 6 to 7 hours of travel time, when you add the time required to find parking, hook up with the SOM tour, or if by train the time to get to the train station, get from the train station to hook up with the tour, get back to your accommodations at night from the train station, etc.

Agree with Kent, although both cities are worth a visit, neither is well-suited as a base to explore the other, or much of the rest of the country. Austria looks small on a map, but those mountains slow down transit times significantly. If you have a timeshare option, my advice would be to pick in which destination you would like to spend the most time, then perhaps spend one or two nights in the other.

In deciding which city would be good to have as a base in order to make fun side trips from, I would prefer Salzburg. Some side trips I would consider would be Munich, Hallstatt, Berchestagen (Hitler's Eagle's Nest and salt mine), Mondsee, St. Gilgen. There are several castles in the area such as Schloss Herrenchiemsee (a King Ludwig castle west of Salzburg by Prien). I haven't personally toured any others there, but just looking at a Michelin map, I can spot several "schloss" locations. We have also been to the concentration camp, Mauthaussen, which is east of Linz. We were in the Salzgammergut area last year and enjoyed the mountain scenery and the cool weather. Either city has a lot to see and do--I just prefer Salzburg because of the proximity of the mountains and because it is a smaller, more quaint city. Have fun!

Thank you for your input, it helps to hear from veteran travelers as this will be my first trip to Europe! :)

I just got back from a trip to Bavaria/Salzburg. We stayed in Salzburg for 3 nights and had a great time. Look into the Salzburg card(Euro 34?) which allows you to get into many attractions such as Hellbrunn Palace(fun), Salzach River cruise, HohenSalzubrg, Mozart places, and a ride to the top of the alps in Untersberg(very nice) and includes all bus transportation(except we had to pay a little extra on the way back from Untersberg). I figured it out and we saved money and there were many other sights we didn't get around to seeing. I agree that the Herrenchiemsee Palace in Prien is a great place to stop(between Salzburg and Munich). The palace is very ornate and the boat ride to it was very scenic.