The most friction came from merging (e.g. when files were changed or project config was changed), due to xcode's insistence on having a project file listing all files etc. The other friction was in the annual update cycle of both xcode and the apps we built.
But the last time I tried xcode it was pretty bad; on paper the new UI coding approach is great, but in practice the live preview was so tempramental and crashed so often it was barely usable.