detailed review about this lens here.
I love fisheye lenses and I frequently used the VCL-ECF1 fisheye adapter on the dedicated 16mm pancake lens. I have previous post about the photos taken with this rig. For lighting I used a twin flash adapter:
I read on photo forums that this adapter can be used on the new 20mm lens, which gave me the idea to use it on the 30mm macro lens (since I don't have the 20mm pancake lens).
How does it perform? I like it a lot, but it requieres perfect composition, good lighting and nailing the focus well (despite the good DOF). Maybe the keeper rate is much lower, than with other lenses, but if you want to take something new, not just the standard boring macro photos, it's the lens combo you should seriously consider.I had only few hours to try it but I see a great potential in it.
Few photos below to convince you: