hmm, the air dodge can leave you vulnerable, rob is to floaty to make it on the stage safely with an air dodge.
The main benefit I see from this is, when using an up+B to recover high over the stage, or as a "defense" option when pursuing someone to the ceiling.
Scenario 1: You recover high, over the top of the stage. A char with a decent jump & U-air is below you, awaiting your descent/predicting the aerial you are going to use to cancel your up+B. Tossing in a *rising airdodge* adds a mix-up.
Scenario 2: You are following a Snake as he cyphers high. You mess up somehow or other, and can now airdodge up and THROUGH the Snake as he descends with a D-/B-air; as opposed to eating it near the ceiling of the stage and possibly getting KO'd.
Scenario 3: You are recovering from below, and manage to get a rising U-air off that hits the opponent. Typically, you will drift onto the stage into some sort of landing action. If your opponent SDI'd the U-air and recovers quickly, this CAN leave you open for a quick aerial from them; whereas you can utilize a rising airdodge to land safely onto the stage and buffer into whatever you desire (shield, spotdodge, d-smash... whatever)
Scenario 4: You are pursuing someone off the stage, and mess up the timing/spacing on an aerial out of your up+B. You can airdodge UP, thus not losing (and actually gaining) height to enable you to pursue your opponent again, with the possibility of safely AD'ing through their retaliation.
More to the "make it to the stage w/ an airdodge": We all know (or should know) that you can drop down a bit lower than normal from a ledgedrop, jump & airdodge at such a height that you kind of "scale" the stage wall (term used loosely) and land on stage JUST as the airdodge ends, allowing you to buffer into whatever the situation calls for.
I don't mean to say this is SUPER AWESOME STUFF, just pointing out that its a valid mix-up.