The 28-135 is the better lens.. but that is also because the 17-85 ( which i often defend) probably represents a missed opportunity by Canon to make a much better than kit lens especially given how much it costs
Saying that , It is better than the Kit , with a good build and USM and IS (which rocks) and AF is reasonably fast accurate and silent but as a lens, it inst the sharpest knife on the block and barrel distortion at 17mm is a bit naff (to be polite) : unless you get it really cheap it is often compared with the "Cheap but quite cheerful" Sigma 17-70 which is better VFM , and cheaper
It has been described as kit lens optics with IS by the POTN crowd but I think that is an indictment of it rather than fact
The Canon 17-55 which also has IS and USM and a constant 2.8 is in a totally different class ( but it costs £5-600+)

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I do have both the 17-85 and have use of the 17-55 ... no contest really
If you have a 70- 300 you would be missing out on the wide end by getting a lens which starts at 28mm ( on a crop) and its range overlaps with the sigma 70- 300
There is also the 24-105L but it isnt liked by everybody