I spent the best part of a year working on the Totara team and the report builder is the main thing I miss so am really pleased to see it aiming for inclusion in M2.4! It was sad that it was originally proposed for M2.3 so hopefully it won't miss the next release. It sounds from Simon that Totara 2.2 is pretty much ready now though, and I guess that was the hold up, so it's looking more feasible now.
We also commonly have a requirement to build in organisational hierachy and allow users to run reports for their level of the hierarchy. Things like divisions, teams, branches etc, are easy enough to do in Moodle with a little customisation by setting up a group of related custom fields, and I think Totara Report Builder will report on custom profile fields natively.
If/when an organisation hierarchy plugin is built for Moodle then it would require a Report Builder source to be setup, and from my time working with Totara I remember these are pretty simple to build, and Simon has kindly added information to the Wiki. I think we used to estimate about 2d developer time to build a new report source, on average.
A common requirement we also get is for scheduled reports by email, which Report Builder does.
The real attractiveness of the Report Builder is that users can build their own reports using an easy to use visual interface rather than writing SQL queries. This is what I miss - we can easily create custom reports for our customers but the reality is that they would much rather build new reports themselves.
The average LMS Administrator among our customer base is not a developer with SQL knowledge, but they do often have people at their disposal who could setup new reports using SQL and I do think this would be a valuable feature if the security concerns can be overcome.
I don't have detailed knowledge of CR but it sounds good. A very useful response from Alex re the comparison, thanks
Simon, if it is not possible to put the report builder code public at this point (but if you are pressed for time then I'm sure there will be no shortage of volunteers to identify and strip out the Totara related code ) then is it possible to just get the T2.2 report builder code to Juan for evaluation? it sounds like he needs to make a pretty major personal decision about whether to continue developing CR, which is a significant decision not just personally for him but for the Moodle community too.
Great to see this ticket moving along