Sigma are certainly not doing too bad. The original 30mm was one of the greatest lenses ever.
Mine was a dud; poor AF performance and a squeeky focus ring. It did however produce that fabulous bokeh
I now have the Siggy 50/1.4 and 20/1.8. Both of these are fabulous lenses and I have no issues with them whatsoever, they are exemplary copies.
Now for the 35 mm: I had the 35/2 from Canon but it was was an old, second hand copy that was less than stellar. It made me wonder if 35mm really is the focal length for me, but these new lenses make me re-consider.
The first results from both the new Canon 35/2 IS and the Sigma 1.4 seem very good. Price-wise they are roughly in the same ball-park so that makes it very interesting to compare them head-to head. I consider the compactness of the Canon a real advantage though, it doubles as a good low-light lens for travel (the example shots on the Canon website are typically the kind of photo's I'd use this type of lens for).
5D3, 5D2, Sony α6000 | SY14 f/2.8, Ʃ20 f/1.8, 24 f/2.8, 35 f/2, Ʃ35 f/1.4A, 50 f/1.8 I, Ʃ50 f/1.4 EX, 100L Macro, 17-40L, 24-105L, 70-200 f/2.8L IS II, 1.4x II, 70-300L, 100-400L | E-mount: SY12 f/2, Ʃ19 & 30 f/2.8 EX DN, 16-70 ZA OSS, 55-210 OSS, Metabones SB | FT-QL, AE-1P | FD(n) & FL lenses.