This is very much on the money. Code reviews often fall into the trap of people discussing and dissecting things that they are comfortable with, while ignoring

This is very much on the money. Code reviews often fall into the trap of people discussing and dissecting things that they are comfortable with, while ignoring the difficult aspects. For instance, reviewers often dissect the elegance and variable naming to death while totally ignoring how the change has been tested (unit tests can show some issues, but if the tests themselves are not covering the core aspects of the problem being solved, then they are not hugely useful, particularly in duck-typed languages like python). Also, changesets that are large but can't be broken down into smaller ones because of practical constraints cause 'code review fatigue': people will review the first few commits/files with gusto and lose steam by the time they are reading the critical code which may arrive in a later changeset or file!)