Once it’s up and running it’s fine but importing photo libraries into Photos is truely the worst software experience I have ever had. It took me weeks of on and off tinkering to get my partner’s photo library setup correctly and syncing with iCloud Photos. The worst part is that when it does fail there’s absolutely no indication to the user what went wrong. At best you’ll get some kind of generic error message, at worst it just hangs forever. Perfectly demonstrates how Apple’s “it just works” design philosophy falls apart when it doesn’t just work.