Parametric cells are great, shared cells are great using them in practice isn't so great.
Parametric cells are stuck on the level, color, line weight and any other attribute associated with the "shared" cell within the file. So to save file space if i want to have 50 of the same thing that are all the same line weight on 1 level and then 10 alternative "options" for that thing on another level with a different line weight... forget it not going to happen.
Of course you can drop status on the parametric cell of course then it's editable but all the variations I so painfully built to on the fly update the design get dropped and when things change i have to re-place the cell and re-do anything I've done with it for attributes. In a strange irony if i make 2D parametric cells then extrude them in my model those DO let me move the object to new levels and change all the attributes.
It would be super helpful if when you place a shared cell there was an option for it to be "pseudo-shared" and all the basic attributes could be adjusted without changing the physical geometry. The geometry could still be owned by the shared cell portion both those other attributes could be owned by the cell instance. Honestly i bet if you asked most Microstation users would prefer it to be this way ALL the time for all parametric cells i know our firm would.
If some how this IS an option in raw Microstation then I apologize we're using the "microstation-mode" within Openbuildings designer, which i keep being told is JUST like Microstation.