Measure looks interesting, but unless I'm missing something (very possible), I would still consider inkscape unfit for CAD work. The chief problem is that if you try to position an object by coordinates, you're positioning the bounding box, thus outside the lines, rather than down the centre of the lines. This is most frustrating with simple rectangles and squares, where "adjacent" objects end up butting-up to each other rather than sharing the same coordinates for some of their points. Thus really you have to work point-by-point, which then means you have to do all the maths yourself. All that said, I might be mis-using it, or there may be tools I've not spotted.
For simple 2D CAD work, the best I've found is librecad, though it's well worth watching the youtube videos because using it is very different from a vector graphics program like inkscape.
Don't get me wrong though - I really like inkscape and think it's a great tool. But even with all the measurement tools in the world, I wouldn't really consider it for CAD work.