Those extra controls exist on other types of TVs as well. That's not the "difference" for using such DVDs with plasmas. Calibration DVDs intended for normal users don't go into dealing with those other controls (such as gamma) a lot because (1) they are difficult to explain, and (2) you can easily get into trouble tweaking those without a measurement device to double check what you are doing. That's why some TVs hide those extra controls away in "service" menus.
Here's an example of the type of difference I'm talking about: When setting white levels with the Contrast control you generally want to crank up Contrast so that whites don't look gray. However you don't want to crank it up so far that you lose white details. The narration on Avia concentrates on the specific symptoms that will show up in a CRT-based display when you are overdriving the whites -- blooming or spreading of the beam which cause fuzzy smeared areas in bright whites and inadequate power supplies which cause geometry problems in the image when high white levels are displayed. Checking for the first signs of such problems will enable you to set an upper limit on how you might set Contrast. Plasmas, however, are not subject to either such problem and so you'll never see what Avia is telling you to look for. With plasmas the thing you want to watch out for as an upper limit on Contrast is "thresholding" or loss of the ability to distinguish near white from pure white. The Avia narration makes only a brief mention of how to use the moving off-white bars to check for that.
If you really want to try tweaking the more exotic controls, you should first gain experience with how the image can be improved or damaged using the regular controls -- i.e., train your eye to know what a properly calibrated image looks like using the regular controls. Then do some studying as to what those other controls actually do.
Ovation, publishers of Avia, also publish a much more expensive version called Avia Pro which is targeted at professional calibrators. It comes with a thick manual of explanations. There's a thread in the Power Buys forum which includes some excerpts from that manual if you'd like to get a feel for the complexity of that sort of stuff.
But most home calibrators are not going to feel comfortable futzing with things like Gamma levels.