I bought this old guy used at a very cheap price (300 Euro) and I think the quality/price ratio is absolutely fantastic. On a 30D (1.6 crop factor) the range is a bit odd and not-so-wide, but I like 35mm and 50mm primes, so I am satisfied with it. Bokeh is awesome, colour rendition great (for my standard of course), solid built, I couldn't ask for more at that price!
My only complain is about flare, I don't know if it's only my copy or if it's a well documented problem for this lens.
Anyway, if you want a fast and cheap zoom lens, and you would use it on cropped sensor cameras and full-frame too, go for it. 20-35mm bros (17-35, 16-35, 17-40) are surely better but at this price it's a bargain!