Don't really expect any help or advice, but just needed to vent.
Dropped over 2.5K in November on a D600 and a 24-70mm lens. My first paying job was a kids' party and I was surprised to find that I ended up with a good number of out of focus images. The problem seemed to come and go, so I put it down to user error and getting used to a new camera.
Did a few totally unscientific tests thereafter and all seemed well, but shot my last wedding of the year last Friday and looking at the results today, once again, a fair number of shots are focussed perhaps 3" behind the subject.
Finally got scientific with a tripod, self timer and a ruler tonight and there's definitely an issue, but it's also definitely intermittent. I can calibrate the body to -20 which solves the problem but may cause issues the other way given that the issue is intermittent.
Emailed the HK sellers tonight (DigitalRev with whom I must have spent tens of thousands over the years) and must now just sit and wait for a response. Very, very pissed off, mostly with myself, but also that a brand new £2600 camera and lens should be so far out. Not as pissed off as my client would be if they ever found out how much coverage they'd lost though.