Somehow these seem the same to me, except nether does what I expect.
I have a wall with a 18" long shelf centered on the wall, I want to increase the length to 22.5" leaving it centered on the wall. No matter what I do the length increases to 22.5" (scale factor 1.25) and the center of the shelf shifts 2 1/4" to the left (I started the scaling on the left side of the shelf).
The top shelf was scaled uniform, the bottom was scaled about the center. scale ctr.skp (33.2 KB)
Hold the Ctrl key, drag the handles, let go, then enter the scale factor, whew.
And with the uniform scaling, following the same advice, everything gets scaled, length, height and width, how is that different from picking the diagonal handles?