I had met a very respected photographer from a well known community college who had also tried out the Olympus E-3 and 12-60 lens and subsequently purchased it. He sat down and showed us his photos from his recent trip across Spain with it and I can only say they were wonderful, if not breathtaking. I was especially impressed with the way the camera handled shadows in alley ways and in architectural details. And he is very pleased with the system.
Nick Devlin, in a review on this site, has also produced some remarkable shots with his G9 recently in Japan. Obviously there are many competent photographers who have produced stunning results with all sorts of equipment.
Most photography enthusiasts already have equipment. Decisions to upgrade, or buy into another system, can be based on anything you like. Quentin apparently bought his E-3 on a whim. I imagine others would buy an E-3 because it's simply an excellent all-round camera which is very portable. Some might be duped by the fact that all Zuiko lenses really are very sharp, not realising that they have to be at least twice as sharp as the equivalent 35mm lens
in order to produce the same results as FF 35mm with the same number of pixels. Others want to know just precisely what advantages relating to image quality an E-3 might have compared with their existing equipment. I'm one of those.
I'm intrigued by the 2 stop DoF advantage of the E-3 system. I think it's possible that a good Zuiko lens could deliver sharper results at f5.6, with the 10MP sensor of the E-3, than a 35mm lens at F11 on the 5D, even if the reason is only due to the opportunity to use a faster shutter speed because of the wider aperture.
However, I'm doubtful that f11 on a good 35mm lens would be less
diffraction limited than a good Zuiko lens at f5.6. Or to put it another way, I'm doubtful that a Zuiko lens would have less significant aberrations at f5.6 than a 35mm lens at f11. Likewise comparing Zuiko f4 with 35mm f8 and Zuiko f2 with 35mm f4.