I had read about four shortcomings of the K-01, but could not resist the $416 price for the 40mm XS lens kit. The problems included slow autofocus, the rubber flap door, no viewfinder, and the bulk of the camera. I received it yesterday. My thoughts:
1. Firmware 1.01 helped the autofocus, and it seems fine in low light.
2. The rubber door is not a curreent problem. Any worry about its fragility will be solved by ordering an Eye-Fi card.
3. I am a viewfinder person from way way back. No viewfinder will either make or break the camera for me. I am going to give it a good try.
4. The camera fits well in my hand, doesn't seem too bulky, though someone with small hands might be uncomfortable.
I lifted the K-01 with the XS lens and compared it with my Olympus OM-D EM-5 with the 10-50mm lens, and the Olympus was heavier. I then put the Panasonic 20mm on the EM-5 and it probably weighs two ounces less than the K-01 and XS combination. Finally, I took a picture or two.
Okay, so it isn't really heavier for the tiny XS lens. But people to agree that APS lens are much bigger and heaver than m4/3 lenses. I looked up the statistics and tried to find equivalent lenses, at least in quality or price as well as focal length. I'm sure one could make many criticisms of my choices, but it was interesting as well.