The fact that one commit = one merge is ridiculous. It encourages monolithic commits for no reason other than that the tool demands it. It's unrealistic to ask someone to code review multiple commits per feature, and if you tie in your CI it doesn't make any sense to run your build over and over again for a single feature either.
The patchsets DO allow you to see the history of a code review if you have to make changes, but I'd much rather see that live in my git history rather than in Gerrit's history. It's a dirty solution to have to amend your commits to make changes.
Nowhere does the author mention how painful it is if you finish a feature, are waiting for a code review, but have to start the next feature using the code you just wrote. Maybe I'm missing some magical feature in Gerrit that makes this easy, but if you push multiple dependent commits to Gerrit, and one of the early ones gets merged, all of the later ones now have to be rebased because Gerrit created a merge commit in the middle.