I've tried it for awhile, and thought it to be pretty good.
I did deadlifts and uhm.. shoulder presses? on it.
Also think I did squats and benchpresses or something like that.
Anyway, two things:
Use big compound excersises.
Make sure to make a very moderate weight selection. If done correctly, the "sensation" of the GVT, starts to come around set 7 or 8.
If you try it, you'll know what I mean.
Important to not go to heavy.
After all, you're going to complete 100 reps.