Maybe it's just me but I've been filleting fish for 30 years, rinsing them in fresh water and vacuum sealing them and they taste great. I don't let them sit in fresh water, just rinse them off at home after checking for any bones and as far as I'm concerned there's no effect on taste whatsoever. I also pat them dry with a paper towel to wipe off any excess water. Keep them dry when vacuum sealing. I've had fish after six months using a food saver and they taste no different than cooking them fresh a day after being caught. In all honesty, if you handle your catch right and keep them on ice, they'll taste fine. When I fillet them at the dock, we always grab a bucket of salt water before heading in and make a salt water slush just by adding ice in a 5 or 10 gallon bucket to put the fillets in while filleting our day's catch. When they're all done, they get put in zip lock bags and immediately placed on ice. At home they get rinsed, dried and vacuum sealed and put in the freezer other than what we plan on using for dinner that night or the following night. Those we'll keep in the refrigerator never for more than a day. Vacuum sealing fish makes a HUGE difference. Like I said, using this approach I've never had issues with fillets other than maybe ling and Spanish mackerel which really don't freeze well at all no matter what you do.

Dakota