Bet it'll be more fun this time around Mike.
Longest I've been there is 15 days back in 06 with my daughters senior high German class. There was only 6 of us (with some other small groups) and we drove all over, in and out day after day from middle and southern Germany, Austria, Switzerland even Lichtenstein. Not much we didn't see.
That was the last time I was able to do any decent amount of walking.

These days it's the mailbox and that's about it. :dunno:
We actually were in Vienna at Schönbrunn Palace during the day and found they were having the free Vienna philharmonic concert that night. We hopped on the wonderful public transportation in the city that evening and went back to attend. What an AMAZING time that was! (Except for the part where I ended up separated from my daughter and the group for 45 minutes, 3000 miles from home, and don't speak a word of German!)

If ever in Vienna during the summer that concert is a MUST SEE!