Lou, as you know I have the trinity 14-24, 24-70 and 70-200 f/2.8 Nikkor lenses.  For what I do I have found the most used lens to be my 24-70.  If you are happy with the Tamron then I wouldn't buy the 24-70 Nikkor.  However, that is by far the best of the 3 lenses.  Just remember it weighs in at about 1kg though so its a brick to lug around.
You do have to be careful of distortion and lens flare with the 14-24 and from what I've seen it is a lot better suited to FX rather than DX.
I'd also look out for 17-35 f/2.8 Nikkor.  Haven't played with one but they sound good.  The 17-55 is a DX lens so if you are thinking of the future and maybe FX later on then this may be something to avoid.  Other than that it is also a very good lens.
				
			 
			
		 
			
				
			
			
				MY15 Discovery 4 SE SDV6
Past: 97 D1 Tdi, 03 D2a Td5, 08 Kimberley Kamper, 08 Defender 110 TDCi, 99 Defender 110 300Tdi[/SIZE]
			
			
		 
	
Bookmarks