I don’t think SIGMA lenses ever tried to compare with Canon or Nikon high-end lens, they just want to let the consumers have the second choice.
Most of my lens are Canon L lens, which is good to have, especially when I shoot at weddings, f/2.8 and / or IS lens are very easy to work with.
I bought a SIGMA 30mm/f1.4 (around $360.00USD) last week and I’m pretty happy with that lens. To compare with Canon 35mm/f1.4 around $1300.00 USD, I saved almost $1000 USD. Personally I think Camera just holds the film/Image, lenses make some difference, but the picture’s layout, capture experience and feeling are what make the pictures stand out.
Share some pictures from my Canon 350D 30mm/f1.4 lens
1/40, f5.6 ISO800 AWB
1/4, f5.6 ISO800 Blance=Flash you can tell the color is redish
1/8, f5.6 ISO800 Blance=Flash you can tell the color is redish
1/8, f5.6 ISO800 AWB
1/5, f5.6 ISO800 AWB
1/4, f5.6 ISO800 AWB
1/6, f5.6 ISO800 AWB
1/6, f5.6 ISO800 AWB
1/8, f1.4 ISO800 Balance=Flash you can tell the color is redish