Summary: I bought 2 of these, one for each of my E-M5's. I first thought that they were a one trick pony, but I was wrong. I have used these connected to a H1 zoom as a Lav mic for weddings. These things are killer if you can hide them.
Excerpt: we got the mics in good time - they have more gain than the built in mics - and the units come with ext cords if you need to clip them to the person you are recording - they don't need any ext power - just plug them in -- they work great - in stereo
Excerpt: Using this microphone was a little frustrating because the quality wasn't as good as the inbuilt microphone for the sony voice recorder that I had bought. There is a lot of ambient noise and just doesn't seem to be able to pick up decent audio. It's quite chunky, and from what I have found it doesn't have any accessories for wind protection.
Pros: Long Battery Life, Reliable
Cons: Bulky, Picks Up Background Noise, Poor Quality Sound
Excerpt: This microphone is great for scratch audio. Have purchased it for my Red Scarlet - plugs right into the front and works without batteries. It is not directional, and captures a lot of atmos but that's what's expected. For what it is, it is an exceptional product. It was used at a 21st I was filming at (loud music and all) - and the sound came up fine. Could hear birthday messages to camera over the loud music quite well.
Pros: Compact Design, High Quality Sound, Reliable
Excerpt: I've had one with my WS311 recorder. Unfortunately, it has been lost. I am now ordering another one from B&H. Fell in love with the previous one. Delivers great results. Could pick up weakest sounds across the room. Wish it was a bit cheaper though. Otherwise, stick to it. It delivers better results than recorder's built in mic. Thanks B&H!