I agree with Burrman -

Even though MoI is intended as a fast concept modeler rather than a CAD system, even an artist will have certain base dimensions in mind when drawing a car, a building, or a product.

Let’s say I'm designing an iPod and I start with a 2" by 3" LCD display. I want that LCD rectangle to show as 2 x 3, regardless of its orientation. Now I want to play with my design and try another screen size - so I edit the screen rectangle to 3" by 4". I would want to select the rectangle, change the size, and not worry how my drawing is positioned.

Same idea would apply to changing the size of doors and windows in an architectural drawing to elements having standard dimensions.

For me, the bounding box dimension would have little meaning in these situations. For odd shaped objects or multiple selections, then the bounding box dimension is the one to use.

Hate to suggest adding complexity, but perhaps a way is needed to show both dimensions, or set a preference option to show one or the other.

Ed