I've had a GF1 since right around the time it came out. Have the Panasonic 20mm and the Oly 45mm. The Olympus cameras including the OM-D just don't do it for me. I like the "tank" feeling the GF1 has. Been thinking about picking up a GX1. Am I going to see a big difference in the newer sensor as far as indoor shots (higher ISO)?