cheaper than the 28 1.8 in canada and you get a 10 year warranty. pretty hard to beat and the image quality holds up right next to the canon 35 1.4.
Canon 28 1.8 vs. sigma 30 1.4 is like comparing shit to a diamond. Sorry, but most of Canons lower end lenses suck to be honest. They mainly focus most of their attention into lenses that are L lenses and even then some of the L lenses are not the best. The Sigma comes out on top in terms of sharpness, flare control, build quality, it's also faster than the Canon 28mm.
From what I have read though the sigma 30mm really doesn't do as well with FF bodies as it was made for digital cameras (meaning not 35mm format). That's when the Canon 35L would be better than the Sigma 30.
my 50 1.8 shits on a 50L i know soo many people on potn that have downgraded from the 50L. stop being a fuckhead and saying all cheaper lenses suck.