Howdy. Got my GX1 two weeks ago. Really a great little camera. Immediately swapped the kit lens for both the Sigma primes. They are a bit odd focal lengths but usable. Size, speed, image quality, all very good. Can't wait for Sigma to make more MFT lenses. 10-20 and 150-500 would be nice for starters. So far I've been shooting mostly with Panasonic FZ8 and later my compact Canon S95. Still use it on some situations, like the Uriah Heep Legends gig yesterday. Been shooting with Canon A-1 also and have some FD lenses. So obviously had to get the FD-adapter. After some quick experiences these seems quite usable, specially on the longer end. With the 400/4.5 + 2x converter I can see to the next zip zone.