I bought the sigma 30 from digital rev . . . . and at the last minute I popped the 50 f1.8 into the basket. I rather regretted it, but never got around to cancelling it.
Lenses arrived yesterday after their typical quick service - the sigma looks like just what I wanted for a small lens, IQ looks perfectly decent, and I'm glad that everybody else has a 'loose bit inside'!
The 50 f1.8 is quite a different thing . . . I was disappointed that it was a little large - and very silver. Still, good build quality, fast focusing (and quite close) . . . . then I remembered that 75mm is actually my favourite focal length on the Leica. Anyway, this lens is fantastic - lovely feel to the images, decent bokeh, quick fast focusing. excellent!
1600 ISO f2.2 1/125
1600 ISO f1.8 1/250
1600 ISO f2.8 1/80
100 ISO f2 1/640
1600 ISO f1.8 1/125
100 ISO f5.6 1/40
if 75mm turns you on I can't recommend this lens enough on the NEX7 - excellent.