Bought this lens back in 2002 (Canon EOS version) and used it for 5 years for weddings and commercial work.

Autofocus speed was excellent, and the f2.8 aperture allows Canon cameras use their high precision x-type sensors.

Image quality was very good. Contrast not as good as similar L lenses but perfectly acceptable. Sharpness was truly excellent when stopped down to f5.6, and usable wide open. For the price this is an optically impressive standard room. Pincushion and barrel distortion well controlled. Vignetting acceptable wide open. Some CA, especially in backlit scenes, but correctable in RAW with software.

Front element does not rotate during focusing so ideal for filter use.

Had no problems with reliability (have had stuck aperture diaphragms on other Sigma lenses but their customer service was superb). Unfortunately, a severe drop led to a misaligned internal element, which caused a left/right discrepancy in focal field. The lens was given away to a friend who still uses it for landscapes (stopping the lens down remedies the focal plane issue).

With a budget of around £400 for a standard zoom this lens is definitely worth considering. The real option is whether you would want to sacrifice the fast aperture for some form of optical stabilisation.

Comes with an excellent padded case and the lens hood is included.

In conclusion: Superb optics for the money, great AF and very well made. However, it's robust rather than bomb-proof and doesn't have the features of some more modern lens designs. It's great value for professional use but there are smaller, image stabilised lenses that may suit general hobbyists better.

Note: battery life is really N/A but I've given it 5 as there's no image stabilisation to cause accelerated battery usage.