I've taken the plunge and bought a tin of Army Painter Quickshade - Strong, after seeing the results on other blogs and have experimented with it on one of my French HaT line battalions. It seems to engender strong opinions, but I thought I'd give it a go anyway. I'm still not convinced that it's more economical or more effective than a bigger tin of varnish from the hardware store, but I'll look into that in the future.
I found that the best way to spread it after dipping wasn't the prescribed flicking, but blowing on it after letting the excess drip into the can. I tried the suggestion of holding it with pliers while dipping and flicking, but obviously that's what you should do with metal figures, not plastic. The base of the first figure got a bit mangled by the pliers. The pictures in this posting compare one 12-figure battalion which has been dipped, with one that hasn't. I've then compared a close up of 2 of the same pose.
I know it's not to everyone's taste, but I quite like the effect it gives, especially for the skin. It defines the creases and folds of cloth well too. I like my figures to look a bit campaign-worn and not too shiny and new, so I think I'll keep on dipping the rest of my collection.