This is only for close-up & macro work. So would the SB-R1 kit be more suitable? I'm happy to stay with Nikon. I understand that the SB-R1 would work on the D610 & I wouldn't need the R1C1 commander kit?
Nikon UK - Speedlights - Remote Kit R1 - Digital Cameras, D-SLR, COOLPIX, NIKKOR Lenses
There are always different preferences and opinions. My first notion is that EVERYONE obviously needs a good hot shoe TTL flash for walk-around bounce for general purpose use (so you are really talking to the wrong person.

) Others do have other opinions, but my own opinion does Not favor ring lights, even for macro. Because it is such a very frontal flat flash. However, if using two of them (like the R1 kit), the lighting could be made less flat by dialing down one of them (on one side) to be a stop or two less in the commander menu.
But yes, the kit is made for macro, and this is Nikons solution. and obviously, many do like it. The flash is not a hot shoe flash, it instead mounts on the lens. Or rather, on some lenses - those with internal focusing. The R1C1 kit is the R1 kit plus a SU-800 commander (or the D600 internal flash could be the commander). Then you would set the Group for the D600 builtin flash to be MODE "- -", to disable its contribution to the lighting (it still flashes commands).
Point is, the R1C1 manual is at
http://support.nikonusa.com/app/answers/detail/a_id/13851 (same as R1 except it includes SU-800 commander).
See pages 13 and 14 regarding mounting compatible lenses. See first sentence at top of page 14.