The problem with long zoom lenses is that they typically don't have a very wide aperture, which makes using that big zoom in low light a bit tougher. The Panasonic FZ300 doesn't have the biggest zoom lens on the market, but it does have a 24x f/2.8 lens that'll reach across the concert venue and still be able to capture crisp images without blurring or resorting to a high ISO, thanks to that bright aperture.
The FZ300 is the successor to the popular FZ200, which has the same lens and sensor. But while the excellent lens specs are still the same, there's a lot of upgrades in the 2015 model. 4K video, for starters. The high resolution video can be recorded at up to 30 fps for up to 30 minutes, or it can record 1080 HD at the smoother 60 fps. The FZ300 can also pull 8 megapixel images from the 4K stills, when the 12 fps burst mode isn't enough to capture just the right moment.
The body has also been upgraded--the FZ300 is designed to stand a bit of weather. The sealing makes it resistant to splashes (though not submersible). Dust and sand can wreak havoc on a zoom lens, but the extra seals means the FZ300 should be able to head to the beach without a single grain of sand creating a lens error.
Speed is a plus here too. Panasonic's Depth to Focus technology helps calculate the distance to the subject so that the contrast detection autofocus can lock on even faster (the manufacturer claims a .09 second autofocus). That 12 fps burst is just excellent as well. Shutter speeds will hit up to 1/16000 on the electronic shutter.
While most super zooms also include manual modes, the FZ300 can shoot RAW, and process the files in-camera as well.
The Panasonic LZ300, so far, looks to be a solid camera. While the LZ300 has the better lens for low light, the Nikon P900 has an 83x zoom to the LZ900's 24x. For another $200-$300, the Panasonic LZ1000 offers more resolution and low light capability with a larger 1" sensor.