Since I really only paint individual miniatures these days (no batch painting, in other words), and since I've never been happy with the old "blue-tac and a cork" system (which only did one thing consistently for me - let the miniature fall to the ground, usually at the worst possible moment), I picked up one of the GW painting handles a few months ago to give it a whirl.
Long story short - I find it excellent. The handle is chunky, so I don't cramp up holding it in my hand. It holds the miniature firmly, with no wobbling or shifting. It's easy to switch miniatures into and out of it. I now have two of them, and will probably get another couple in the coming months. Love 'em!