It does depend on the scope and how long you've let things "clutter"
I let myself loose for about a year focusing on adapting to my new surroundings and for all practical purposes, letting inspiration soar!
I finally locked down and took a solid 2 weeks to get things in order and separate my home "context" from my work "context"
data points per your request:
- project/reference file ~100 folders
- inbox empty
- 51 projects
- 57 not now (or someday) projects
- 126 next actions
this 3rd week is primarily to clean up any loose ends and get ready for take off come the new year
btw, pls don't let "2+ weeks deter you" - I'm guilty of processing on the run to some degree - one of the no nos in DA's book. I also took some time to evaluate the GTD outlook add-in, capture and design a system to address weak points of my previous setup, as well as capture the transformational process as a series of mindmaps...i did it - just don't ask me why i did it!