I don't like the way they are marketing these. If you (like I) bought the fisrt two as a set, you got a special package deal (a good thing). But now, you have to either buy them in the package of four for a deal, or buy the two new ones indificually. Why not a "deal" with the two new ones as a package, for those of us who already have the first two?
I'll end up getting them anyway, because I like Tony's workout style, and I need more non-step cardio and shorter workouts I can use in a crunch or to 'mix-and-match".