One topic that has come up in this consultation is Gerrit improvements. Why can't we make improvements to Gerrit to fix our problems with it? Isn't Gerrit upstream making improvements?
I've added some additional rationale that I felt was missing from this proposal to a subsection to the "Why" section of the document. This hopefully explains my perspective as someone involved with both the GitLab proposal and as someone who's involved with the maintenance of our Gerrit install.
The core of the issue is that we are rather singular in our use of Gerrit. The other companies running Gerrit are Gerrit developers -- this is the level of familiarity required to perform administrative tasks and add features. Maintenance and upgrades (in my limited experience) require non-trivial interaction with upstream to perform.
Simple improvements like avatars, renaming users, or renaming repos are either not support at all or implemented via plugins with varying levels of support. Bigger improvements I'd like to see like two-factor authentication and anti-vandalism tools are not on the upstream roadmap at all as many installs are either protected by Google's authentication or behind firewalls. We are the only large open install using LDAP authentication which I worry about constantly.
Further, upstream technical decisions (as is likely true for any project) are sometimes questionable. One technical decision that, collectively, the Gerrit community is still realizing the ramifications of is forgoing a traditional RDBMS in favor of NoteDB. This has led to multiple problems ("external id already in use" for example) and is somewhat broken for our use by dint of an upstream bug that has been open for 2 years at this point.
All of the above is to say that while I see Gerrit improving in its UI and UX, administration is difficult and key features are lacking and I see little reason to believe they'll ever be addressed. Should we stay with Gerrit, we need a non-trivial dedication of resources to drive forward any new features we'd like to see.