Yes, the Banyan Tree is really magificent. However, you can just pull into the parking lot and see it among others right along the parking area, without paying for any attractions. We took really neat pictures of the trees.

The tour part is really pretty good, especially for seniors. It was not geared towards kids at all, but for us the weather was just perfect and they (ages 7 and 10) behaved. The tour guides we had really skimmed over the lab area, and the museum part where the inventions are is self guided. The focus of the tour seems to be the homes and grounds, which, though somewhat interesting, are not particularly grand or anything.

Also, currently, the Edison house is being restored, so you are not allowed in it. They give you a pass for a future free visit, but for us, we probably won't get back before that expires.

So all in all, go in nice weather but not with kids, though they are very impressed with those trees!