I can certainly see the utility in Jumpy's suggestions, but they don't cover the case that I struggle with most.
For example, if I'm developing shapes with complicated interactions between parent (group) and child shapes, I really need to be able to see what cells are changing in value, live, as I move something, and correlate that with which formulas refer to what. This is inordinately hindered by being able to see just formula, or just value.
-- Graham