I think it would be a good addition to optionally apply labels to the rating grid options. Right now they are numbered 1...n, so you can have a scale of, say, 1, 2, 3, 4, 5 as your headings on the grid. I think it would be useful to label these, such as Strongly Disagree(1), Disagree(2), Neutral(3), Agree(4), Strongly Agree(5).
I have some code that does this. I'll post it as a patch. Be aware that it performs well on the back-end (i.e. survey display, and input) but there is no support for adding labels in the management GUI.
There's now a patch for this, but not complete ...