Yup, on my current build i went as far as to weigh all the balsa parts, and mark their weights on them. That way I could use the lighter wood at the rear and towards the wing tips, with the heavier wood nearer the CG point. By using a short kit, you can then be a lot more selective about what weight wood you are using, and how much of a certain weight wood you will use instead of being forced to replace or use it somewhere you don't want to. I should have replaced some balsa sticks on my current build as I don't think the strenght I need is there on the rear deck.

One of my next build will probably be a short kit.