I have not been impressed with the books. Quite the opposite. Mainly, I blame Baxter, who despite his qualifications seem to have a very poor grasp of science, and maths in particular.
When you introduce a huge change like the long earth, it is important to keep the suspension of disbelief running. The number of simply dumb mistakes in the books are just too huge.
It starts off with the people emigrating to other earths. The authors make a point of how people step at a rate of 10-15 minutes per earth, yet we meet settling parties in places that would take decades of constant stepping to get to. Clearly, no one thought to work out travel times when stepping, even as they were writing a book about traveling through stepping.
I can forgive the impossible airships, they are just too cool, even if pressure-changes between worlds would shred them in short order.
But not getting exponential growth? I mean, just not having heard of the concept? I don't know how long it would take Trolls and Elves to fill up the long earth, but it wouldn't be long. A hundred and twenty thousand years after the first Troll/Elf is born, all the earths are deserts, at a guess.
Stuff like saying the long earth has a vastly bigger surface area than a dyson sphere? Baxter is supposed to be a mathematican, 500 million >>> 4 million was too complex for him?
Its not that any of these are terrible, its just that when everything is not just wrong, but very wrong, and even the really easy stuff clearly hasn't even been looked at...the sheer sloppiness is offputting.
The stepper town would have been hit with every plague in history, untill they developed a psychotic hatred of strangers. Aslo, Romans on an empty earth with 2000 years to work, and they got a couple of little towns?
I didn't much find the human beings very convincing either. Joshua is just too self contained and passionless to be interesting, and the people in general...hardly anyone finds being a bandit rewarding, with instant escape handy? Vast numbers of people in the western world suddely finds farming a rewarding profession? Entire network of towns with no jail and no idea what to to with a murder?
And for all their mention that the long earth is not tame, it seems most people can get by as long as they are sensible. It basically seems based on our own, tame world. The actual consequences of earths with their entire suite of predators intact, with no fear of man, doesn't seem to have been give any thought.
The books read, to me, like sloppily written childrens books that got published for adults by mistake. I keep getiing jolted out by the "Lord, no!" feeling I get when I run into something particularily suspension-of-disbelief wrecking.