>The problem with Nikon cameras is a person always wants to >get another one and go one better. >I currently have a D90 and really like it. I have been looking >at the D600 for a while now, and today I receive an email from >Nikon advertising a deal with a 24-85mm for $1999. >What do you all think?
I have a D90 and bought the D600 when it first came out. The difference IS night and day - focusing speed, image quality, low light performance, 2 card slots, etc. - and if you already have DX lenses, it has 'auto dx' built in. You can still use all your DX lenses, albeit at a lower megapixel size than FF at 24megapixels. It's still plenty for most shots. Then start saving up/building your full frame lens collection for the next couple years.
I have a stabilized Sigma 17-50 2.8 DX lens. I use it with my D600. A frame appears in the viewfinder showing the DX size. I get better image quality with my DX lenses on the D600 than I did with the D90. I have a Nikkor 55-300 VR - it's still an 80-450mm in DX mode on my D600.
The only real disadvantage of the D600 is if you had say, a 70-200 FF lens - it's no longer a 105-300 on the D600. So you lose some reach on FF lenses by going to a D600 instead of a D7000. If you shoot a lot at distance it's something to seriously consider.
The D600 is more finicky about settings, for example, depth of field is more critical.
I use the U1 and U2 on the dial to quickly change from shooting, for example, 4000 ISO available light to 400 ISO and flash. Don't have to go through menus (same as D7000).
The kit lens is good quality with the exception of image distortion according to Pop Photo. I bought body-only. I have a nikkor 85 1.8 D and a couple old FF lenses from film days that work fine on my D600.
Or wait for the D7000 replacement and stay at DX...the D90 is still a fine camera. I'm keeping mine as a backup.