in regard to AC7>>AC9 it is still the same program. Main difference is the use of View sets instead of PMK files for use in Plotmaker. Try to fully understand the enhanced view set concept which incorporates the view options and dimension preferences as well.
From memory the calculation tools have changed a bit.
The Detail tool is useful for automatic cross referencing but is not on the critical path for Archicad usage.
Get to know Solid Element Operations. Again not a critcal feature.
That said, your productivity will go up using the the last two features
Some older library parts may not work as expected
There are numerous other small traps and enhancements.
Cheers John
John Hyland : ARINA : www.arina.biz
User ver 4 to 12 - Jumped to v22 - so many options and settings!!!
OSX 10.15.6 [Catalina] : Archicad 22 : 15" MacBook Pro 2019 [/size]