My dad once said to me, "You give a lot of books three stars." I do.
If I were a fan when Warner was first publishing the series I think I would have been disappointed with this ending. The mystery is OK, some parts are pretty easy to guess, but some of the mystery is pretty subtle. But there's no resolution with the characters. It's just like any other Boxcar Children book. I guess that made it easy to continue the series.
I read a mix of the series (original and continuation) as a kid, and I remember liking them. I'm trying to get the nine-year-old to read some, but she's not that interested (even though I keep telling her they're mysteries and she likes mysteries). Oh well.