I also am somewhat skeptical, Lance. The art of hovering is learned by the brain making connections between visual clues from outside the cockpit, other sensory inputs, and your hand and feet. Since the Heli-chair wouldn't provide the same inputs, I would think that it wouldn't get you all that far.
It does take most students about 10 hours to get a stable hover, but that is not "hours and hours" of practice -- that's 10 hours of all kinds of flying. Typically a lesson wouldn't have more than maybe 15 minutes of hover work (anything more would be torture!), so that equates to 2.5 hours of actual hover practice.
And then there are people who get it right away -- I once met a pilot who works for Forbes (and who taught Harrison Ford to fly in an R22) who trained as a civilian at a British military facility, and soloed in 8 hours. That's right, he not only could hover, but he could take off, land, do turns, and do autorotations, in just 8 hours!