With Logitech's design it truly is a waste of plastic.
What wheel do you have?
Depending on the wheel, if it a Pro or G25 for example, then you just won't be able to hold the wheel in place. It will act like a great Thigh-Master, though, so if you need to squeeze something hard, then go for it.
Even for the much weaker DF, I was only able to hold it in place for a very short time before I threw it into the box.
It's a terrible design, but I have seen a custom-designed one made out of wood here that, if you have no other choice, would work much better because you sit on it. The new Porsche 911 wheel has H-like wings, too, which may help with that wheel.
If at all possible start thinking about a proper wheel stand. It doesn't need to be complicated, elaborate nor expensive to work well. Check out the great designs people have made in the Cheap Stand thread. They are award winners!
Cheers,
MasterGT