I have narrowed my decision down to these two drives although I am open to having my mind changed. I have a M1 Air base model and do nothing extensive only music, spreadsheets, email, YouTube, Facebook. The price for the Shield 4TB on Amazon is $299 and the price of the Sandisk 4TB is $374. I am trying to decide which to buy. I am leaning toward the Shield because of the price. Any recommendations on which one to buy? Thanks.