Some cars are notorious for their depreciation straight off the lot, so don't fool yourself. There was a time when you could knock 25% off the price the minute you signed the paperwork. And as I pointed out, when talking about automobile recalls it's often a matter of owner/operator safety, which this certainly is not. I went through a series of Dewalt drills, all of which had the drive mechanism strip within 3 months. At the end I was able to ask for a full refund and went elsewhere, but only after making a stink with the company and the retailer.
Here's the thing, no one has ever said what percentage of D600's were effected. Here's a piece from the folks at The Camera Store comparing the D600 and D610, and according to him
not one of the multiple D600's they sold ever had a reported oil issue.
Yes there were problem cameras, I had one, but as is pointed out the internet makes things always seem worse than they truly are. I know for a fact that there are people here who returned theirs out of fear and not out of any real problem, reading about the issue while the camera was in transit and immediately seeing what
had to be oil and dust on the sensor. The sky is falling, apparently.
Again, I'm not denying the problem, and I do believe that while it's a PR nightmare for Nikon I find no issue with the way they've handled it so far. It sucks that cameras like yours and mine had to go back multiple times, but to hear that for folks like Hark they made good after the 3rd trip and offered credit of the initial purchase price towards a D610. It's not a great way to do business, but it's a normal way to do it. If your problem persists then I wouldn't blame you for seeking a replacement.
I would love to see numbers regarding total number of D600's sold vs. the number of cameras returned with problems. I suspect the percentage was very low - far less than 1 in 10 - and the real impetus for the D610 came from big retailers like B&H and Amazon who had to deal with a rash of returns and cancelled orders from folks running scared. Regardless, it's water under the bridge. Camera companies don't do recalls - they just don't. The logistics of collecting and evaluating every single one of them is staggering. There is no dealer network like you have with automobiles, and a huge percentage of owners never left their house to buy the camera and e-retailers aren't about to act as collection points for servicing. You can want it to be be any way you'd like, but the reality is, as Mick sang, you can't always get what you want.