Hi raider
At the risk of stirring a hornet's nest, try defining the term "better" !
I've never actually handled the DA12-24mm myself, so it would be pretty unfair to comment on it's abilities when attempting to compare it with Sigma's 10-20mm. In my case, it just so happened that a long-standing C***n-owning friend had sent me some photographic examples featuring his Sigma 10-20mm lens. Viewing these images, I instantly realised that I simply had to get one too, which you can take as a ringing endorsement of the optical quality of this Sigma lens. However, I completely concur with the previous comments stating that:
Quote: Landscaping with it (Sigma) is tougher than I thought it would be.
Thus far it has been my experience that when photographing landscapes, this type of lens often has a tendency to almost appear
too wide (through the viewfinder) on many occasions, which is where the invaluable "zooming" facility of the Sigma comes into it's own for perfectly framing a picture. A fixed focal-length wide-angle might obviously not afford such an option without a great deal of legwork, although many would argue that prime lenses offer the ultimate in sheer optical quality. All things considered, such a decision will be both a personal and financial one which only you can arrive at......good luck whichever path you follow !
Best regards
Richard
P.S. See link below to view one of my hand-held photos taken with Sigma 10-20mm as an example of foreground subject leading the eye into the rest of the image:
http://s242.photobucket.com/albums/ff156/Tamron18-250mm/?action=view¤t=IMGP3633.jpg