I also recently had the opportunity to test the Sound Shark Parabolic Microphone in a typical classroom setting. I found that it really helped to get that louder volume from the distant speaker when compared to other microphones that I would have traditionally used.
Now while a Parabolic microphone will definitely pick up distant sounds better than any other type of microphone, it should not be considered a replacement for other microphone types. It really should be considered a different type of microphone and possibly one you may want to add to your audio kit. If you're interested in listening to other examples, you can find videos on their website at http://KloverProducts.com/SoundShark.
The unique shape of the parabolic collector is used to collect incoming sound (pressure) waves and focus them onto a single point where the microphone converts the collected sound energy into an electrical signal. Because the sound energy from a large area is focused onto a single point, the sound is in effect, amplified. This is the same technology that is used to capture the sounds of the game during professional football games every weekend.
After shooting a few projects with the BlackMagic Design URSA Mini 4.6K camera, I found several that I could sometimes get away with just the audio from the built in microphones. But as soon as I threw on my Canon EF-S 17-55mm F/2.8 lens with Image Stabilization (Ursa is not full frame), the camera microphones would pick up all of the IS noise. Once that noise was embedded into the audio, it was no longer usable. So I set out to find a good microphone that I could mount over the handle.
I personally wanted the shortest shotgun microphone, powered over XLR phantom so I didn't have to worry about batteries. I wanted to find the slimmest shock mount so it didn't sit too high (trying to keep the camera clean and simple). It didn't need to be the best microphone in the world, as I was only planning to use it mostly on camera for good scratch audio or sound bites. After reviewing a few options I found the Azden SGM-PDII to be a good fit and has excellent customer reviews. Over at B&H they have an Azden SGM-PDII Shotgun Mic Kit that includes the shock mount, and the microphone already comes with a short XLR lead.
Running through the tests mounted on camera, the SGM-PDII was completely free of any Image Stabilization noise from my lens. So for my on-camera needs it works great. And surprisingly I found the microphone also sounded very good when booming overhead, so it's something I would even use during interviews. If you're working with a camera that has built in XLR inputs (i.e. Sony FS7) and looking for something better than the built in microphones, you may want to take a look at the Azden SGM-PDII Short Shotgun Microphone.