The HC-V520 and 520K are the same model. The K designates the camcorder is black in color. The 520M is a model that is not sold in the USA and has an internal memory.
By Panasonic Team on December 9, 2013
I did not have any problem with motor noise so far. I use zoom a lot since I use my camcorder recording my son's marching band, although recently I started using a separate digital recorder for better audio. I hope this helps.
By Imok's Gear on March 30, 2014
Yes, this camcorder records in either AVCHD or iFrame. Additional information is available in the below link. http://service.us.panasonic.com/OPERMANPDF/HCV520_ADV.PDF#page=2
By Panasonic Team on March 6, 2014
I believe it will. However, the main point of this camera is its powerful zoom. Do you need such zoom for indoor dancing? I believe that the camera is suitable for such application. How far from the subject you are?
By Roni Gzanda on January 3, 2014