I bought this lens a couple years ago when I bought my Elan 7. As a poor student at the time, it was a significant upgrade from the cheaper kit lenses. I knew from experience that a particular shot I had been after for years (Salisbury Cathedral) could not be made with a 28mm and was determined to get it on my next trip. The shot was captured, I was happy and the print hung on my wall for years.
The bulk of my photos are made when I travel, and I don't travel resort-style. This lens has made some long hauls with me, including a serious 8-day hike in remote Newfoundland and 7 weeks in South America. It has served me faithfully and delivered phenomenol results for the price. The lens has been dropped on rock, soil, asphalt and sand and never missed a beat. (My heart did though, and I learned a few new curses each time.)
The extra 4mm on the wide end has proven to be extremely valuable. You do get some very small rounded marks in the corners, moreso if you use a polarizer. But rather than hang the prints on your wall as is, take the time to have them cropped slightly by your processor.
The results I have obtained with this lens are very sharp, with excellent contrast and colours. This is so even in some less desireable conditions. I shoot on film and custom crop my enlargements. I have been able to make some extreme crops (8x10 blow up with a crop of 50% of the original image) and still retain good detail.
If you're a pro who needs to make a living off your photos, then you should invest in an L-series model. But if you're like me and can afford to take a few crappy shots, then this lens will serve you well.