I just got home and found an email from WD. There claim is that the HLFS is cable compatable to the GLFS with the advantage that it can also be plugged into a backplane. They also state that the HLFS does have a heat sink like the GLFS. They blamed BestBuy for retail fraud.
Well, my take is that while the HLFS is mounted to a heat sink, it doesn't have the finned heat sink on the end of the drive like the GLFS. As far as retail fraud, all of the boxes I received were shrink wrapped and the drives in the boxes were in heat-sealed anti static bags.
If you ask me, they're passing the buck.
From looking at the specs on the website, the drives are identical, it's only the external 3.5" casing that is different. Both have heatsinks as part of the external case, but different designs due to the one being designed for easy use with a backplane.
BTW... you & I can easily buy everything online that is needed to create the illusion of a "Factory sealed" product, which is why some manufacturers use customized sealing products. IIRC, from store shelves, WD uses generic shrink wrap, & the last one I bought had generic anti-static bag & sealing sticker. Shrink wrap, anti-static bags, stickers, etc... all just a click of the mouse & a credit-card number away for you & I.... even easier for a retailer....
BTW... the HLFS is the more expensive drive due to the customization for direct use with a backplane.