Differences between WDBAAY0030HNC-ERSN and WD30EZRX (3TB drives)?

Well I ordered this item and it arrived today however I noticed that its the older version of this model so I am wondering if I should return it for the new model?

I am mainly worried about noise levels as this is going in my HTPC.

I don’t think you will find any diferrence. You can compare the specs on the link below.

http://support.wdc.com/product/install.asp?groupid=608&lang=en