Only somewhat related, but I'd pay decent money to have access to the whole Piper/CitC/Critique/Code Search stack. As much as I've tried to like it, I just don't really like Github's code review tool.
It also has some UX snafus that cause reviewers to write a number of comments and then forget to publish any of them, leading to a lot of interactions along the lines of "I thought you were going to review my PR?" "I already did?"
It's great if you have a team that does code reviews. It works less well for reviewing contributions from external contributors on an open-source project,a as the contributor likely just wants to get their PR merged and doesn't want to learn a special reviewing tool.
No affiliation, just a happy customer.