Good fill flash, surprisingly powerful for it's size. Also can be used as a trigger for the remote flashes. I was skeptical at first, but impressed after use. It does sit a bit too close to the camera, so it produces red eye and can show a shadow from a physically longer lens. It is perfect for point and shoot photography and in no way a replacement for the higher end flashes. It is perfect for what it is designed to be.
Not the most powerful flash but compact, light and good for fill. I use it on PM1, PM2, PL/7 and OMD EM-5. It does use the camera battery so it will reduce the number of shots you get from the battery in the camera. It does not clear some of the lens hoods so you have to remember to take the hood off to avoid spoiling the shot or use a different flash that is taller. It does not pivot to bounce, but for a small, light flash to carry its useful when you need it and you don't; have a taller one.
I thought a flash this tiny would be worthless, but it actually works really well for average indoor shots and outside as a fill flash. The flip-up to operate is a handy feature, as you can easily turn it on and off just by tilting it up or down. It has worked so well for me for the past year that I haven't spent the money or time to find another flash for my camera. It operates off of the camera's battery, so you don't have to worry about carrying or charging another battery for the flash. A great little flash!