@Prophet: The idea is that you land a grab while you're facing the edge of a stage, yes. If you're facing away, then you can do the traditional bthrow, this just opens up the option to get the same effect while facing the other way, at low percents. And it can follow DI fine, you can sh in either direction at this low of a percent. Even if you don't feel comfortable with trying to land the disable (at this low of a percent, DI isn't quite as much of a factor regardless), you could just judge accordingly and start chaining fairs.
@Tres: This differs in that the disable has MORE knockback at lower percents and can be used while facing forward as opposed to only backward. Also, this isn't a question of how easy it is to grab a spacie as much as another option to do with said grab. Taj manages to grab good spacies all day, partially because he's Taj, but it just illustrates the point that it's quite possible. And it doesn't even have to be exactly next to the ledge; the disable has a surprising amount of knockback at low percents and with stages like YS, etc., practically the entire map is near a ledge.
I encourage everyone to actually get on their Gamecube and actually try and test this before they criticize it.