I make absolutely no excuses for not finishing this book. Any book that's this boring after more than 100 pages deserves all it gets. The characters are very forgetable and I find I have no interest in finding out what they will get up to at any point in the future. If this is the first in a series of books about the long earth, it's no excuse to claim that maybe we should give it a chance and wait for the next one to see If things improve. If a novel hasn't grabbed me by the time I'm 25% or more into it then I'm very much afraid it simply isn't going to and the authors should be grateful I gave it that much of a chance before casting it aside.
Not good. It's tedious, the characters are bland and uninteresting, and quite frankly, endless worlds with no people in them was never going to make for a good story in my view. This is a book that should never have made it past the starting post.