I have both G1 and GF1. The way I use them, I leave the 20mm on the GF1 and use the G1 as the interchangeable lens system (I have the 14-45 and 45-200 and other M-mount lenses). So when I want to go light, it's just the GF1/20. If I want some flexibility, I'll take the G1 with a couple of lenses. When I feel really strong, I'll take out the Canon 20D!🙂