BUG: the font sizes don't change. The ParentFont property is True, but changing the Font.Size on the form does not change the size of the fonts displayed in this control. Also, nothing happens if you change the Font Size value in the object inspector. It seems to be locked at 8.
ADD: grid lines (both sides, not just the left)
ADD: a flag that says to "select item on edit". When you hit the enter key on a value cell and it's not empty, the cursor goes to the end. It would be good to have it select the text in the cell when it opens so you can easily replace it. This is a very common default editing behavior.
ADD: an option to allow Tab to go to next Value field and open it. for editing. That is, navigation should be more like moving between fields on a form. This is rather confusing to use without a mouse because the cursor goes to different places when you click Tab depending on where it is and what the state of the field it's on.