I've bought one of these recorders (Tascam DR5) to record separate audio while I'm filming Ganga Aarti at Varanasi next month.
I hope syncing of tracks is easy to do, not something I've tried before, would probably need more sorftware, Nero15 is my only experience with editing.
My plan is to place the recorder on a mini tripod the first night and record it but not film the hour long ceremony, just watch what the priests do.
second, third and forth night, I'll be filming, each night from a different angle. Not sure what I'll be filming with yet, a bit of everything
(Osmo, GoPro4 black and Nikon D5300).
@Ricardodaforce - I love your Osmo timelapse, are you using the official DJI tripod?