I read and enjoyed Piers Anthony's Mode series back before I was old enough to recognize how sexist and gross his writing was. But I still appreciate the imagination behind the setting, loathe as I am to ever revisit those works. 
 So I'm happy to have read The Long Earth, which employs a similar plot mechanic: what if similar, parallel universes existed, and were suddenly made accessible to (almost) everyone? 
 There's a few moments where the suspension of disbelief is strained. On top of "parallel universes happen, just go with it" there's also, quite conveniently, (view spoiler)[a giant unlimited-funds corporation run by a singular super-artificial-intelligence, whose mind (it claims) originated from a person. Consciousness uploading and "strong" AI existing in isolation, with no world-wide technology arms race to produce it (hide spoiler)] seems more outlandish a conceit than parallel worlds. 
 But it makes for a good story, and I'm looking forward to reading the sequels.