must have for 1.6x bodies

I tried a 28-70 on my 10D but always ended up frustrated because it was too tight, especially when shooting indoors and in crowds. After a lot of reading and debating I found a used 17-40 for $600 and jumped on it. What a great lens! The first big test was a large anniversary party. It was very easy to squeeze into a crowd and still get great shots of people that were only 3-4 feet away. It is also very useful as a walk-around lens in good light.