I've been looking to see if other D610 users have had problems with AF. Today I've taken mine back to the Nikon repairer to have a look as it previously worked really well on AF-C for taken photos of squash players. Super sharp then all of a sudden AF-C does not seems to work and the sharpness on the photos is terrible. I hope they can fix it.
I'm interested because I tend to fight the outer focus points of my DF, but the body is new to me so I'm still trying to determine if it's user error or AF error.
Jason - it was not resolved. Though I have a new D610 which is better in terms of AF. It just seems more reliable, and 2 of 3 of my lenses now do not need ANY focus fine tuning. With my last D610 body they all needed quite a lot of fine tune adjustment.
While it's a little slow, overall the AF on my D610 is as accurate as my 5D Mark III.
Slightly off topic. A friend just bought a d610 and the focus will not work at all. Sent it back to b&h and they sent a new camera which has the same problem! He is awaiting no 3.... Yes the af is on.