I think, not absolutely sure, but think they are all on/off type pedals, rather than ones that give a volume/expression readout depending on how far you press them. I really like the springy feel of a piano pedal.
But you would have to make sure your VSTi or keyboard supports it. If it is a VSTi, then it is just a midi signal like a pitch bend, but for expression. Then you would map the pedal to that midi control. However, if your keyboard or VSTi doesn't support it, then a pedal will not help.
I asked M-Audio guys and they're on/off switches after all despite the misleading ad copy. On the bright side I learned a lot about how piano pedals work.
And after learning I definitely do want to get one of those 3 pedal on/off switches just to play better in general.
Otherwise for expression I'm thinking I could try putting a spring in my FC-7 and see how I like the feel, that's easy a spring assortment box is a couple bucks, it's on its way as I have other things I'd like to try springs out on too.