Panasonic FZ20 shouldn't be compared to Canon S1 IS. They are in different price ranges. A more realistic comparison is FZ3 vs S1 IS.
Yes, the S1 images are too soft. And, from what I've seen of several sample photos, the FZ-20 produces too much noise for my liking. I really didn't think much of the FZ-20's images (at full resolution).
All these cameras (around this price range) have noise issues. The Canon and the Konica Minolta are just as bad.
The Fz-20 also uses a proprietary (see Expensive) battery, and has no distance scale in Manual Focus. Also, 8 seconds is the longest shutter speed. As well, they still have the Macro setting on the dial, rather than as a separate button. In the FZ-10, this meant it was difficult to use Macro in Manual Exposure mode (there is a way, but you have to 'trick' the camera). It appears as if they've not corrected this stupid problem with the FZ-20. To me, the FZ-20 is a camera that could have been - and should have been - much better. Instead, they were content to simply increase the resolution, and leave the problems of the FZ-10 intact.
Your criticisms are valid but they are misplaced IMO. Most of what you say is applicable to nearly all cameras in this price range and class. Remember, we are talking about ultra-zoom (10x+) cameras and you should compare these within the class. To see what I mean, consider how all the zoom cameras seem to have flaws:
* some don't have image stabilization (and you can't use the high zoom on thse ultra-zooms without IS--or you have to carry around a tripod everywhere)
* some have purple fringing and darkened corners, while others have noise problems at ISO 150+.
* some have autofocusing problems
* some have no macro mode at all
* some have expensive proprietory batteries, expensive memory cards, etc...
* and so on.
It's very difficult to decide between the ultra-zooms because they all have SOME flaw
I think that, in this range of cameras, Olympus has the best image quality, and the best features overall. Too bad they went away from the AA batteries, though.
I don't remember the features of Olympus off the top of my head but if I remember correctly, it doesn't have image stabilization, which is a huge feature (especially if you are zooming past 6x+)!!!