We try to be very accurate in our min / pref / max size computations for many of the controls. For example, to determine the preferred size of a string of text, we actually use the TextHelper, set the text & font, ask for the layout bounds, etc. Perhaps instead we could take the width of a single "W" in the given font and multiply by the number of characters for the preferred width -- much like we do for TextField. This will lead to Labels and Buttons being wider than necessary by default, especially if the label has a lot of text in it, so this might not be a good idea. However making these computations faster, though rougher, could be a significant boost in layout performance.