I never had these kind of performance issues at all. I use it on three different ThinkPads, all not too bad but also no crazy hardware. The cheapest should be an E14 with a AMD 5500U and 16 GB of RAM that was around 500€ 4 years ago.
Isn’t Fusion360 cloud-based? If so, it doesn’t make too much sense to compare the performance on a certain hardware.
I currently switch a lot between FreeCAD and Sims. When I brainstorm with my girlfriend we either use a simple drawing programm or Sims. Then, once we aligned on an idea, I use FreeCAD to bring in accuracy. Quite often then the original ideas don’t work out because of wall thickness, window placement etc.
I currently combine Draft, Bim and Sketcher to plan my house. You can also use Tech Draw and Part Design in some areas. I think FreeCAD has a steep learning curve with all the features it has, but it’s also incredibly powerful.
If you want to do accurate calculations, wall thickness, exact angles, window sizes etc., I would recommend FreeCAD, especially the draft workbench and possibly the BIM workbench if you want to go 3D afterwards.
Tutorial FreeCAD draft workbench (2D): https://www.youtube.com/watch?v=ODEeqtepOwA
Tutorial FreeCAD BIM workbench (3D) as a follow-up: https://www.youtube.com/watch?v=WZHyUBfdgJA
If you are more looking for a rough planning where you can test furniture placements, floor designs and see fast results, I recommend The Sims 4 (no joke!). The base game is free (also available on Steam) and it’s quite easy and intuitive to move stuff around, change a wall, place decorations etc.
The draft workbench and sketcher workbench in FreeCAD are both only for 2D projects.
Okay, that’s strange. When you say workstations, I assume that you had pretty decent hardware and probably more powerful than my consumer notebook. I usually don’t notice lags or load times > 1 second. If I do a complex operation like mass-cloning an object via a polar pattern, I have to wait for 2 or 3 seconds but really nothing that bothered me in the workflow. Definitely never anything close to a minute as you described.
If you want to give FreeCAD another chance one day and still experience the same issues, maybe bring it up in the official forums. The experts there might have an idea what could be wrong.