I use a refurb SSD as the OS disk in my file server. Hasn't given me a spot of trouble in over 18 months of use. I have no idea what constitutes a refurb SSD ... Did they replace chips within it? Or was it just a clueless customer returning a product? I do expect that it was tested thoroughly, though, before marking it and reselling it, so I have no concerns.
I bought some "refurb" OCZ SSDs from Newegg a year or so ago.
Two of them were 240GB OCZ Vertex Plus R2 units, which use a Barefoot 2 controller. I was already familiar with them, having had some 120GB models of the same previously (bought new). I felt that the controller was a stable one (never had an end-user firmware update, that I know of), and that they would be reliable.
I also purchased five 50GB OCZ Vertex2 "refurbs", which I believe were "old new stock" - sold as refurb so as not to have to provide the 3-year warranty support for them. I came to this theory, because 50GB is kind of an odd size, and probably not their best seller, so they probably had leftover stock.
So the 240GB SSDs, had some SMART data that indicated that they had been used. The 50GB, none that I could see.
I did have some issues with the 240GB SSDs, in my Foxconn NanoPC. It has a C-70 APU (9W TDP, I think), which is passively cooled. I used to run it continuously as my HTPC, and the SSD got rather warm, along with everything else in the unit. After a month or two, the SSD had started to develop bad sectors (determined by a surface scan with HDTune), and eventually, some of the OS system files corrupted.
I came to the conclusion that using an SSD in that NanoPC wasn't the wisest idea, and because those SSDs had been worn, the cells had more trouble accurately holding a charge, and exposing them to heat, caused them to develop ECC errors, which showed up as bad sectors.
Doing a secure-erase fixed the bad sectors (I did that twice), and then I put them into my Q9300 desktop rigs that are well-cooled, and never had the bad-sector problem again. (I still scan them from time to time just in case, but so far, so good.)
I put a 30GB OCZ Agility (Barefoot 1 controller, purchased new, used slightly by me) into the NanoPC, and it developed one bad sector too, after a month or two. It wasn't as bad as the 240GB was, probably because the SSD wasn't worn, but it still happened, which led me to believe the problem was the temps, and not the fact, specifically, that the 240GB was a used, worn, refurb.