I agree with Poki, the pre-existing lenses coming from SLR Magic are good but more of a specialty lens rather than for everyday shooting. But the new lenses they have released (since buying out Noktor) are something to definitely watch out for, their recently (re)released 50mm f.05 is causing so much of a stir as of late with images that is on par with the $11,000 Leica Noctilux, they have decided to scrap the old re-branded lens formulation and re-did the lens from the ground up. SLR magic (who now also owns Noktor) is definitely a lens manufacturer that needs to be watched.
If you're looking for a nice 35mm, you can try your luck looking for a 35mm Rokkor (they're bit uncommon) or alternatively Voigtlander have a couple of 35mm 1.4 lenses (M mount) that performs very well with the NEX (the lenses are quite compact too).
Yeah, it's definitely bang for the buck! Just not ideal as your "main" lens. Nevertheless I wont buy another 35mm lens - it's good enough. And with the 16 2.8, the 24 1.8 and the 50 1.8 it's a pretty complete set of fast primes for the NEX.