Aside from one inconvenience, really worth it.
My wife and I went to Frisco on Valentine's weekend. We took the Segway tour, and did the Muir Woods and Saucelito combination, scheduled for 2/14/08. On our first day, we panicked, since when we arrived at the Beach Street location, there was no bus ANYWHERE for the Muir Woods tour. We had to hike around the city for awhile to figure out what went on. When we went to the headquarters, we ran into Alfredo, who told us that someone forgot to CONFIRM our Muir Woods/Saucelito tour. (UUGH!! :( ) He rescheduled it for Saturday, 2/16/08. That was the only inconvenience/dislike of the tour.
Loved riding the Segway around the Fisherman's wharf area. Our tour guide (I want to say Susan) really knew her SF history. We saw some really beautiful parts of frisco.
Then on Saturday, we did the Muir woods. If you like the outdoors, you should LOVE muir woods. Big trees, peaceful streams, etc. Not to mention they filmed parts of Return of the Jedi near the redwoods. (I was picturing the Ewok's coming out of their hiding places the whole time I was there. )
Very great tourist attraction. If you are healthy enough to ride a Segway and are in the frisco area, I would definitely recommend this tour. It is well worth it.