I really can't understand the Sigma "lens-politics" for mirroless cameras. Exemple: Panasonic has an outstanding 20mm F1.7 Pancake. Why I should buy a big, heavy 19mm F 2.8? - 2.8 is what you buy with a zoom lens. Even Sigma itself has a reasoable 18-50mm F2.8 for 4/3. What I'd be interested in, would be fixed lenses that are small and/or have F1.2 - 1.8 as aperture. Something zoom lenses still not offer.