I know I should have checked on this site first. I too was hesitant to carry out the reset option, as the second option was very clear as it said it will format the hard disk, but the first option did not mention anything about the content on the hard disk.
I carried out the reset and the recording on my hard disk were fine. Glad I did the reset as it was giving me grief trying to copy recordings onto my PC. It worked fine after the reset. By the way, it seems to make no difference to the transfer speed when using hard-wired ethernet or wifi connection.