Just last week I got the black travel kit from Sigma. I'm actually quite happy with it! I decided to get it because I have very few good quality brushes right now and I thought having that kit would cover a bunch of the basics, and it was cheaper than the full set. (Though, in retrospect... the full set without the brush roll isn't that much more expensive than the travel. Eh, oh well.)
I read a lot of reviews (including the ones right here!) and watched a BUNCH of videos about these before deciding to go for it. It's weird, so many people seem to have such varying experiences - bad smell, no mention of the smell, shedding or not... That was odd to me.
I guess I'm one of the ones who got lucky. I washed all brushes and didn't get much shedding at all. I've now used them several times and spot cleaned them with no shedding or dye running out. Also, the travel case did have a bit of a leathery smell which also got on the brushes, but... to me it really wasn't that strong or that bad.
Sadly people seem to be having different experiences, as I said. My personal take would be to invest in a set if you need the basics like me, since they're good quality and cheaper than MAC.