Opinions of the 20mm AF speed seem range from "not a big deal" to "unusable". Does anyone out there have experience both the Sigma 30 and the P20? How does the AF compare? I've got the first gen Sigma 30mm and really like it. I have no problems with it's AF speed and I like the pictures I get with it. My only issue is ergonomics. It's ribbed for grip right at the base, and it's super annoying with my GM1 w/ franiec grip. I know the 20mm is a stout little guy, but it's smooth at the base. It will be crowded, but not as uncomfortable. Thanks!