17mm f/2.8 Zuiko vs 19mm f/2.8 Sigma

007 Peter speaks the truth.

I own both a GF1 w/ 20mm 1.7 and
have a 19mm Sigma for the Sony NEX7.

The Sigma/Sony with its 28mm equiv. is a beautiful combination. Couldn't be happier with it.

OTOH, as 007 states, the 20mm on 4/3rds is ideal.

To me, the 20mm f/1.7 is THE must have lens for the GF1 or similar 4/3 bodies.