I am looking for a new light weight telephoto zoom solution right now, hiking around in the jungles of South-East Asia, you don’t want to carry either too many or too heavy lenses with you. The AF-S Nikkor 70-300mm f/4.5-5.6G IF-ED VR has been the accepted champion for some time, but Nikon also offers a smaller, lighter and less expensive, DX telephoto super-zoom, the AF-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR.
The AF-S Nikkor 70-300mm f/4.5-5.6G IF-ED VR has the advantage of being designed for FX format cameras, which means it can be used on both FX and DX camera bodies and it seems to be a stronger build.
The AF-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR is lighter, less expensive and of comparable image quality, but can only be used on DX camera bodies. On a long trek in the jungle I will probably only take lighter weight DX camera bodies anyway, so this may be a better choice.
I haven’t made up my mind yet, maybe I will end up buying both of them.
The following is a comparison chart of the two lenses.