well I had a play with it and wow it sure is wide... however when I got it home and gave it a good testing all was not well. There is a soft band down the left side of the images, having read about this since it seems to be a fairly common fault on this lens. Needless to say it will be going back for a refund, I guess I'll just make do with 17mm at the wide end.

well almost a year later I'm trying again... I've just bought a secondhand 12-24. It arrived today and looks to be in lovely condition, so far I've just taken a couple of snaps with it in the garden but it does look fun. I'll have to give it a good grilling tomorrow but for now here a couple of snaps.

Maybe this help. 35 reviews from Sony-Minolta users, sample images, links to web reviews and tests.
http://www.dyxum.com/lenses/Sigma-12...G_lens122.html

Used to have a 12-24, great lens, i used it to good effect until recently when i upgraded to the 16-35 L series.

Would recommend the Sigma as a low cost alt any-day.