... and I like them. I'm a geologist who got stuck handling all of the lab data for my company. We make building products (think stucco and plaster- lots of mixture designs and standardized test procedures). We're also a small business, and we don't have the money to hire someone solely to handle IT or even to buy one of the commercial packages.
What we've got: a PostgreSQL database that holds data for Manufacturing and R&D.
The problem this solved: reporting.
Originally, I wrote a custom program that queried the database and spat out reports in Word and Excel formats. It was a nightmare to maintain. Want a new template? Write more code. Did the database just get divided into separate schemas for Manufacturing and R&D? Alter source code. I used Pentaho's Metadata Editor to map the database to a set of virtual tables. My report templates (which are much easier to design graphically, even though Report Designer's mechanism for calculating values is rather awkward) query off the metadata, which means that I can make changes to the database itself and simply update the metadata rather than individually update a bunch of report templates. It was more work up front, but doing things this way has saved me *a lot* of time that I would otherwise spend packaging data into reports. This is not the sort of thing you would use for reports where the tests you run are highly tailored to a product being developed, and you need to write a detailed analysis of the project. This is for form reports (like pass/fail QC test reports) where you need something like a product code, a test result, and a red "fail" or green "pass" text color, or project reports where you run a set series of tests and are typically only changing the project name, customer/location, and about a paragraph of analysis.
I've used their ETL tool to batch import CSV files into databases, and it's reasonably straightforward. I do have the BI server set up, tested, and using PostgreSQL as a backend, but it's honestly just not something we use.
Who will do well with this stuff, if your business even needs a reporting solution: can you configure Tomcat, use a database, and muddle through tutorials? Are you reasonably good at teaching yourself new things? You'll probably be fine once you get the hang of it. (The documentation can be a little lacking.)
Who will not: in general, anyone who hasn't configured servers, used databases, or done a little ad-hoc programming is going to be completely lost. Are your coworkers trying to re-implement relational databases in Excel? They're going to have to be taught what any of this stuff even is before it begins to make sense to them.