Why on your own installation
Standard training shows TYPO3 the way it ships. In practice nobody works with that version: there are custom content elements, a page structure that has grown over time, particular permissions and conventions that have settled in over the years.
When the training happens on the real installation, the translation step disappears. Participants learn exactly what they need the next day, and they trip over the unclear spots during the session itself. That feedback is often the most useful part of the day for us.
What editors actually need
The toolbox is smaller than people expect. Create and move pages, insert and order content, place and caption images from the file store, set links, look at a change before publishing it.
Then there is the part that slips through easily and causes trouble later: why a heading level is not a formatting choice, why an alternative text should not repeat the file name, and why a link that reads click here is worthless to some of your visitors.
Training takes place at your offices or in ours in Stuttgart. For teams in Munich and the rest of southern Germany, the journey is a scheduling question rather than a cost.
For development teams
When development is to happen in-house, the subject is structure rather than operation. Where things sit in the sitepackage, how TypoScript and Fluid work together, which extension points are intended, and which interventions come back to bite at the next update.
We work on the existing code for this, because abstract examples transfer badly to an installation that has grown over years.