I bought one at the end of last year. Nice enough, but not really better than 28mm on my 28-75 zoom. 28 is quite wide on full-frame, but pretty much a standard lens on APS-C (42mm equivalent?), hence the reasonable prices. I don't think it is renowned as being a stellar lens, just a steady performer. It is a nice small size to always have in the camera bag. The 24 is supposed to be better but I have had a similar experience with that as well, just a bit 'meh'.
Nex 5, Nex 6 (IR), A7M2, A99 and a bunch of lenses.