I'm one of the people who uploaded a video and I would say while it might not be whisper quiet, especially when the disk spins as heard the first 30 seconds, it is pretty close, and I should note my phone was about 4-6 inches away when I recorded that, so I was very close to the ps4. If someone has a suggestion for a good Android app that measures decibels I will be glad to check that out and report the results back way later on today as I just got to work.
So I would say to those whose ps4 is very loud, call Sony. Mine is a launch model and as you can watch seems to be okay and is not very loud at all. If is not okay and is loud, hell take advantage of that year warranty while you still can. Sure it sucks to be without a console those couple of weeks it would take to replace it, but I am thinking loud now could perhaps lead to other issues down the line perhaps. Or it could just be yours is just loud. Hard to say but if it does worry or bother you, see if you can fix it. If you do get a replacement and it is the same deal, then I am thinking that perhaps points to other factors. Shelf it is on is vibrating, etc.
Good luck.