On the whole I would say that the decision to go either way would be a good one.
I will start off with my prejudice, I am a Canon fan, currently I have Rebel, EOS 30D (both Digital SLR's) Nikon coolpix 7600 and the Canon S3.
I recently upgraded my Rebel to the 30D and was therefore in the market for a good fast auto for my wife (so she wouldn't be using my 30D). For what its worth here is my opinion.
I was looking at three camera's actually the S3 the Sony H5 and the Panasonic DMC FZ30. The Panasonic didn't cut it right off but it may for you, my reasoning was poor button placment and it was too heavy and bulky for what i was looking for, imagewise it was superior to both camera's but that is to be expected on an 8mp camera.
The Sony was my next adventure I liked the overall build quality of the Camera and found the 3 inch LCD to be a nice touch. The autofocus seemed a hair slower to me and camera startup to shoot was about 3 or 4 seconds and the delay time between shots was also evident comparing to my EOS isn't fair but it was my frame of reference at that point. There was no noticable change in speed regardless of the resolution. The zoom was great and the image stabilization worked very well. I printed a couple of pictures from the camera and found them to be clear and crisp at 100 ISO in good light conditions at full zoom, obviously lowering the lighting conditions increased the image noise and produced a digital blurring in some areas, still relatively good though. The camera was a bit bulky for what I was looking for but was further ahead than the Panasonic by leaps and bounds.
My next was the S3, now having the walk through of the sony to compare to. At maximum zoom the same image at 100 ISO was noticably less clear than the Sony (understandable given the differences in megapixals) as I moved up the ISO scale the difference was less noticable and I felt the Canon outperformed the Sony after about 400 ISO. The Sony had a slighty hotter flash resulting in better resolution at further distances but I found it was a little hot and blew out some white (overexposed) at closer distances (under 10ft) The Canon was dimmer at longer distances (over 17ft) but had better close up exposure under flash. The USM on the Canon focused quicker and adjusted quicker than the Sony and I would say about twice as fast. The Canon was much faster startup to picture taking, and I found that it was about 1/3rd faster from image to image at highest resolution. The video from Canon was better but I could care less about that, the frame rate is faster so it was better. The LCD was smaller on the Canon but that comes with a smaller unit and I didn't care, I am taking pictures to print not to view on the LCD. The Camera felt good and was very responsive and fast the digic II processer writes fast to the cards. A pain in the butt is the memory stick thing I am not a proponent of having to use the Sony Mem stick I prefer to be able to shop for my media and the connectivity is easier on the PC than.
From a software perspective the Canon bundle is a little more user freindly and does some cool things, if you are a competent digital picture processer then you won't care but something to think about.
In the end my biggest issue was picture speed, I upgraded from the Rebel to the EOS 30d for two reasons. One was to get better resolution and a broader range of capabilities, but I found that I kept bumping up against the Rebels buffer underwrite speed to the CF card and that was causing me to miss some key candid shots and even some great portrait shots the I could have had with a bit faster system.
So in all the blah blah blah above I went with the Canon. A bit easier to handle for my wife who has smaller hands, and it is a faster camera from start up to shoot and from picture to picture.
Hope that helps