The drive is everything that I expected it to be so far. I bought the drives to to in a Drobo 5N NAS box and the RED drives, which are recommended for this box, are fast. It is obviously too early to tell if they are reliable.
One heads-up that people should be aware of is the warranty. You get 3 years from Western Digital, and they have a dedicated customer support line just for the Red drives. Registering the drives online at their website is quick and easy, but in the case of the drives that I acquired via an Amazon Marketplace vendor it said "OUT OF REGION - Product is outside the region (Americas, Europe-Middle East-Africa, or Asia-Pacific) where it was originally shipped." What it means is that the Amazon Marketplace vendor didn't buy the drives directly from WD in EMEA, but instead sourced them from the Americas or Asia-Pacific. Luckily this isn't a big deal for a home user because your product is still covered by the full 3 year warranty, but you are limited to 5 RMA's per year for out of region products.
Are my 5 drives going to cause 5 RMA's in one year? I hope not! If you had 50 drives you may have an issue though as any good engineer knows the chance of drive failure increases in proportion to the number of drives that you have.
So buyer beware - get a product direct from Amazon and I guess it will be officially sourced. If you do get an out of region product from a Marketplace vendor you will still get support but there will be caveats.