Nothing wrong with frozen fish at all; I have a freezer (em... fairly obviously) stuffed full of a huge variety of fish and meat; makes cooking a whole lot easier when everything is on hand and you can plan ahead. Had a pretty awesome day earlier in the week going down to a seaside town which still has a working fishing fleet, buying a load of fish pretty much fresh off the boat (including the aforementioned mackrel) and then going off to pick a cherry tree I rent,