About model and data exchange with 3rd party solutions: Revit, Solibri, dRofus, Bluebeam, structural analysis solutions, and IFC, BCF and DXF/DWG-based exchange, etc.
Having just upgarded to AC11 (and mac, but thats another story), I am working on a ac10 project with some 100 zones.
The zone schedule, with names, numbers and areas, which takes about 1 min in ac10 to calculate, takes about 20 min in ac 11. same machine, same file, same everything.
I have been running schedules on some very large buildings with no problems at all. One is over 400,000 sf (4000 sm) with thousands of doors, walls, etc. including the complete structure with all the steel beams and columns. I haven't timed it but I would estimate that it takes no more than a minute.
I am not using zones in the schedules however. Have you tried saving back to AC10 to test if the problem goes away?
I build some 400 complex walls to represent construction elements that are applied to interior walls.
Unfortunately, even with the "no effects on zones" active, ac takes 20 minutes to calculate the zones. If I delete those walls it takes about one minute.