I purchase a Katzeye for my d3000 2 years ago as all I could afford at the time was af lenses. I found it to be a big improvement over the standard matte screen, they are really good but not the same as an old style f series focus screen however, just different. I found it didn't seem to affect the af system when using a kit lens, the green dot indicator seemed to be fairly close & also found no change in the exposure but I did get the 'special ultra bright coating' that made it more transparent I also found the only other offerings were from china sellers that seemed to be priced to go if you know what I mean. Made me question the quality. Katzeye are made in Massachusetts on an as needed basis they don't keep a large stock on hand, so when you order, it may take a few days to make it.
Seems that the big guys have no need to make split screen screens any more & rather you just buy a new lens. Darn shame as some of the best lenses are now dirt cheep but you can't use them to the fullest if you can't tell if the subject your aiming for is in focus.
I have been pondering getting one for the 700 but as it has the screw drive I get to use my old lenses & unless I am trying to photograph a subject behind something I don't mf very much.
Since canon can do it maybe if all the pro body owners got together and pestered enough do you think Nikon might be nice enough to make a old school split screen for us?