I’ve bought a couple of refurbs off Amazon before. It’s pretty much what you expect. Cheap, but they are not going to last long. I never used them in anything less than a RAID 6 setup, and they were the first drives to fail and be replaced. They can get you over the hump of having to order a whole set of new drives at once, but you shouldn’t use more than a few and start replacing them as soon as you can because they may cascade under the load of rebuilding your array.

The one unexpected thing is the drive runtimes were wiped. I could verify by polling the last SMART runs which contained the runtime, and they were in the 4-5 year range.

As long as you buy drives shipped by Amazon, you get their full 30-day return policy. Just run a long SMART test when the disks arrive.