Hmm, yet another flash modifier. Interesting idea, although I wonder how much the movable barn door actually helps improve the overall lighting or is it more of a gimmick? It also looks to be quite expensive and before parting with any cash I would want to see how its performance compared with its competitors.
Something like this probably gives similar results and has more options for around half the price.
http://www.amazon.co.uk/Walimex-Pro-Spe ... +modifiers