I tried to go that route many times (using the kitlens more, using the Tamron 18-200 or the Sony 18_200) and my last try was the Sigma 30mm.Me too. I've got both Sigmas on their way, as well as the 50/1.8 OSS. I guess I should give this AF thing a try, after all.
I have to admit: The lens is sharp and has good edges! It is small, black and lightweight.
But the thing with AF on the Nex is.... It just plain s****s.
It is too slow for anything moving and hunts every now and then. Close up work (not really macro) doesnt work well because of the hunting too.
So every time I tried the AF thing on the Nex I went back to my precious Contax G lenses and other manuell focus lenses.
If you use MF lenses often, your focus speed will match the AF on the Nex for sure.
So for me AF-lenses are a no-go on the current Nex line up.
If the AF improves with new Cameras I will surely check the lenses out again.