I just started working with my new Olympus, and I thought I'd throw up a few quick reactions. I know several people are looking into the camera, so here's my opinion on a few issues I was interested in.
I have previously used the Ricoh GX-200 and Canon G10.
Form Factor: great- it's better than I was expecting, but no better than the G10. It feels e bit thinner and wider than the G10, which gives a secure hold with one hand. That said, the non-retractable kit zoom lens adds a noticable inch. This may be vying to replace the G10 (it certainly replaced mine), but you are no longer dealing with the easy to pack and protect brick shape of the point and shoot world. There is plenty of room for case makers to come in and offer RF shaped cases for this little wonder, because no fitted point and shoot pouches will do the job. Right now I've got it wrapped in a Jerry-rigged softwrap pouch with a YStrap. Not ideal.
Live View: works well, and I don't miss the viewfinder much. Haven't tried any noon sun shooting yet though. Olympus did do a brilliant job with the manual focus- it zooms into 100% on full MF, but the real joy is a AF/MF hybrid mode, which is basically AF that switches to 100% fine-focusing is you start rotating the focus ring on the lens. Works really well.
Image Quality: My G10 had already gone on via eBay, so I couldn't do a head-to-head IQ test. So instead I set up my Phamiya P45 next to the Olympus, both on tripods and at roughly equal "normal" focal lengths. Both shot a highly detailed print from 10 feet, 4th of a second at f/5.6, ISO 200. Took several self timer shots with each, all RAW, processed with no sharpening in Capture 1 and the surprisingly similar-looking Olympus Studio Pro.
I down-scaled the Phase One tiff to the size of the 12MP E-P1 Tiff. Bicubic regular resizing.
My unscientific results:
The Phase One images look sharper pound for pound, but not by leaps and bounds. If you use even modest sharpening in C1, the difference becomes much greater- compared to the Olympus images sharpened either with the raw processor or Photoshop CS3. All this is to be expected, given the MP and sensor differences. More detail is always more detail. All things considered though, I would be willing to use the E-P1 for a professional job, in a pinch.
But that's not news- the surprise is that these files were much, much cleaner in appearance than my old Ricoh and G10 files. The small sensor files always seemed to end up with a stilted brick-work structure at 100%. They were beautiful up to a certain size, but just betrayed a wrongness at fine detail. The Olympus pixels just ended up looking like a fine grain structure at 100%.
I imagine it might be similar to the Sigma performance, but with 12 instead of 5MP. I've never used the DP1 or DP2, but now understand their devotees excitement. Great files, small(ish) camera.
I'm happy.