[WolfeReader]

"Changing branches required chatting with the server in most cases, and could take a minute or two."

Which is directly solved by being a DVCS, yes. Your second paragraph contradicts your first.

Darcs and Pijul can change branches very rapidly despite being diff-based, because they too are DVCS (and the inverse patches basically already got computed upon commit, so it's easy on the CPU).

[ltbarcly3]

But Darcs replaces slow branch changes with something that no other VCS has (that I'm aware of), slow commits! Making a commit can take 5 minutes!