I hate the shadow less, over-exposed faces produced by on-camera flash, it can ruin great pictures. As such i decided to give this a go and see if it could help at all. Well, it did, I shoot in RAW and can tell even in post processing that the diffuser helps as it spreads the light more evenly meaning there's less under exposure to the background and less over exposure on people's faces which is great. I have to say though that this would be a 5 star review if instead of the blue and yellow diffusers this was just the white one at a lower price as both he blue and yellow ones are almost useless, their colour isn't nearly subtle enough to give a 'warm' or 'cold' effect, just a sickly looking yellow or an underwater looking blue, they're useless.
All in all this is a great buy if, like me, you want to be able to use a flash indoors, at parties and still get great images. It's at least worth a try for the price.