I still shoot a lot of polaroid and there is nothing quite like it. No grain, just magic. I've had boxes where sheet after sheet were dried and then lo, good sheets! The thing you can count on with expired Pola sheets or packs is, well... nothing. The success / partial success / failure of one sheet will not dictate the prognosis of subsequent sheets. I simply would recommend shooting every last one just to be sure. Best of Luck!