Canon 15-85 vs 17-85

[dbax]

I can only presume your 18-55 was a kit lens? when I bought my 40D the 17-85 was its kit lens! so you might gain 1mm on the short end and 30 mm on the long end but really, to my thinking, your still buying another kit lens.
I'd seriously be thinking about saving some more $$'s and looking at something like( but not restricted to) the 24-105, its an L lens so it has superior build and much better glass.

[ZedEx]

However, 24-105 is a totally different focal length to 17-85 so probably not comparable. OP, look at the Tamron, it is very good quality and you won't be disappointed. To get something sharper, in the same focal length, and with a nice wide apeture, you would need to step up to the Canon 16-35mm f2.8L. Very expensive, quite big and not a big zoom range. As dbax states, the 17-85 was the kit lens for the xxD line, which seems to be slowly shifting towards the 15-85. I would look up reviews and user opinions on both.

I can only presume your 18-55 was a kit lens? when I bought my 40D the 17-85 was its kit lens! so you might gain 1mm on the short end and 30 mm on the long end but really, to my thinking, your still buying another kit lens.
I'd seriously be thinking about saving some more $$'s and looking at something like( but not restricted to) the 24-105, its an L lens so it has superior build and much better glass.