They were only using Red Drives to use up stock they actual have 2 - 3 other drives in those units as well. Its up to them because they are selling a USB external drive you have to pay the higher cost point as far as buying a WD RED drive to guarantee Cache size and warranty.
What Internal drive is likely in any given Easystore
Based on the information I have right now, the following chart is what you're likely to get from a particular Easyshare model, and in the case of the NESN some clarification on them as it seems to change depending on when it was boxed and where.
Easyshare Model Number Ends In... Potential Drive Models
-NESN WD80EFZX (older Made in China), WD80EFAX (older Made in Thailand), WD80EMAZ (Seemingly newer packaged Easyshares), WD80EMZZ (?? A few reports of this drive lately, looking for info on them)