What do you want to do with it?? Do you want to run it off camera?
I looked into this recently, and although it’s a bit more money, decided that getting a proper Nikon flash that will work with the Nikon CLS was worth the extra money.
I looked at the SB-600, but it wasn’t that much cheaper than the SB-700. Had the SB-600 been a lot cheaper than the newer SB-700 then I would have gone for that one, but in the end I got the SB-700.
Am really pleased with it so far. I haven’t had the chance to use it much, but it is very adjustable, easy to set-up and adjust, easy to use in master/remote mode and comes with a few decent accessories.
It has filters for incandescent & fluorescent to match the colour balance, & I think the latest cameras will detect these filters (via micro switches on the flash) and automatically adjust the white balance accordingly). It also comes with a diffusion cap.
I was going to get mine from Bristol Cameras as they were doing it for £250, but Jessops budged on their price & did me it for £260 so I got it from there instead.
EDIT – Oh yeah. Check whether your camera can work as a master for the flash. SB600 can’t work as a master, whereas the SB700 can.