I am an engineer doing 100% architectural design. I can't use MoI for my building plans, since there is no dimensions, hatches. Also, I usually need BIM (Building Information Modeling) technology so that's why I use Revit Architecture.
Moi is my favorite tool for general modeling for my building models, especially for my interior projects (stores, office buildings etc) because Revit is not good at general modeling. I have 1-2 examples in the gallery thread showing what I mean.
I think MoI is a great tool and I will use it very often for furniture modeling, light fixtures, exterior objects, special constructions from wood, gypsumboard, difficult false ceilings, etc.

I think MoI 2.0 will be even better with object handling, grouping, maybe some more 2D functions etc... So it's worth having such a nice tool