Hello prasadsabhavat, and welcome to the friendly Camera Labs forum!
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I have the 28-300 myself (see my review
) and it's a very versatile lens. As I now also have some experience using a 24-70 from my visit to Venice (see there
) and it turned out that 28% of the shots with the 24-70mm were at 24mm plus I used the 14-24mm in 13% of the shots. So this might be an indicator that at least when visiting a city 28mm might indeed be too long.
But if you complement it with a 10-24mm like PauloFeitosa_Curitiba suggested you have a very powerful combo that should cover almost every situation.
Unfortunately there's one thing to keep in mind: when changing lenses you might lose precious moments and miss the shot and it's also an opportunity for dirt getting into the system. So if you#re looking for a real all-round zoom for your D7000 get a Nikon VR 16-85mm or VR 18-105mm.
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews
, My Pictures
, My Photography Blog