Hi guys,
I'm new here to the forums as well as to dSLR photography. I was recommended to sign up here by a member on an unrelated forum. Anyhow, I've just purchased a Canon XSi and I'm now looking to get a new lens and was hoping you guys could help me out.
At first I was set on either the Sigma 17-70 or Canon 17-85 but after browsing through this forums, I'm now intrigued by the Sigma 18-200mm (Canon just came out with its own 18-200mm but at $699, I would rather go with the Sigma considering the raving reviews it has received so far).
I'm basically looking for a good walk-around lens so that I don't have to swap lenses all the time. I figured the 18-200mm would give me more range but because of the longer focal length, my IQ might be compromised a little bit. I've read some of the threads on this forums but I'm still a bit confused between the two. What are your thoughts? Which would you get? Please advice.
Thank you! 

