Regarding the original question - yes, I'm gravitating that way.
When I bought my NEX7 is was with the intention of using my legacy Nikon and OM glass on it (but not my M glass). Most of my first year's shooting was with an OM 24/2.8 and 50/1.8 MIJ which gave me excellent results.
But, I also wanted a native AF lens for everyday use. I'm not a zoom person, so I picked up a Sigma 30 and fell in love with it. Later I picked up a Sigma 19 and like it, too.
I've been off recovering from surgery, and now that I'm back I ordered a Sigma 60 to complete the kit. These three will form my everyday carry kit.
I think the Sigma DN lenses are excellent regardless of price.