We took a ride on the Spirit towards the end of their season, and thoroughly enjoyed it. It was one of the "cocktail cruises" so we had a beverage or two and had a few of the snack options. You book inside or outside seats. The folks at the cruise office were very accommodating when we ran into weather and scheduling issues.
This was the first time we'd been out on one of the cruises since we began boating on the lake 13 years ago. I found it very relaxing to be able to just sit back and enjoy the ride.