24-105 on crop body

I currently have the 17-85 IS and I love the range. But I have found though that the performance at 17mm, especially around the edges, leaves some to be desired. I am seriously considering upgrading to the 24-105L, but I'm concerned about the usability on my XTi, as it would then be a 38-168. This doesn't leave much on the wide end, so I would probably also pick up the Sigma 10-20. So I'm wondering if it's worth dropping $1500 on a 2 lens combo to replace my current one lens setup. I don't do any professional shooting a the moment, just as a hobby. To those that have the 24-105 on a 1.6 crop body, do you find yourself looking for something wider as a walkaround? How much better is the 24-105 over the 17-85 really?

Let me just say this, it's pretty darn usable. I used the 24-105 f/4 on my 30D and it went pretty wide, so if you're also picking up the 10-20, you're going to love it even more.

why dont you set your 17-85 to 24mm and see how it is?

The 25-105 was the first good lens I purchased and although its a great lens (probably the best 'everyday' lens there is) it isn't wide enough on a crop body. So I bought a 10-22 and then replaced that with a 16-35. Since you already have a good 70-200, I don't think you would ever regret getting the 10-22, 24-105 combo.