I have the 15-85 and I agree with both John and Brendan: it is a great outdoor lens. The only issue I have is that it is not wide enough for indoor ambient pictures; the 17-55 is much better in this regard.


Personally, I chose the 15-85 because of the focal length range: alot of pictures can be taken in this range. At the wide end 15mm is actually noticably wider than 17mm and the extra 20mm at the long end comes in quite handy.


The 70-200 f4 IS is also a great choice, particularly if you don't have the funds for the 2.8 or want something a bit more portable.


Stephen