Well, I have not used the S3, but recently used the S2. I bought an H5 and my friend has an S2. She wanted to switch cameras for a week, so since I could still take mine back, I decided it was a great idea. Great way to try both cameras.

First on the Canon. It is definitely faster. faster start up, faster pic to pic times and the multi burst is absolutely awesome. You can fill up a 1 gig card in like 2 minutes and there is no processing time at all. The Sony, you can only take like 7 photos in a row before it has to process them. That said, however, I noticed that I had a much harder time getting focused photos on the canon. Very few of the Sony's were blurry, and those were definitely my mistake (like had the flash off). I had several of the canon photos that should in no way have been blurry! And they were. very disappointing. Also, I noticed that there were a few photos that were horribly overexposed (maybe my fault as she did not give me the users manual) and they shouldn't have been.

She mentioned to me that she has had to "learn how to take photos" on this canon (coming from a sony previous to this). I didn't feel that way with the H-5, however, I had a sony prior to this camera, too.

The macro mode on the canon was terrible. I couldn't get anything focused. The sony, you can practically put the camera on the item and take a clear photo. Have heard, though, that the S3 is better on macro than the S2. But I cannot say.

Another difference, that I found odd, was the movie mode. Canon needed processing time after you stopped filming. Sony does not. I was surprised that the canon would need to process the movie since it seems to be an all around faster camera. But it needs a few seconds, where as the sony, when you are done filiming, it is ready to do whatever you want.

I have really struggled over which camera to buy. But I hated the tiny viewfinder on the canon, the eyepiece was horrible and didn't like the blurry photos. I do like the shot to shot time, though. However, I decided to keep the sony for a few reasons: 1) I love the 3" screen. 2) I like the way the menus are set up and like the over all feel of the camera. 3) the flash automatically pops up. The canon does not. You have to open it manually even if you have the flash "on". it won't pop up. I hate that. If I have the flash on, I should not need to pop it up myself because most likely I won't remember to do that!!! 4) I like the smart digital zoom. I wanted a high zoom and love the fact that I can get an even higher zoom if I drop the megapixels down 5) I already have memory stick duos from my other sony and last but not least 6) the need of taking 100 photos in 2 minutes is very small for me, in fact probably nill. So although it has a much better multiburst, I would probably never take more than 7 photos in a row anyway.

I suggest you go to a store that has both cameras and play with them. See which one you like better in your hands, and which one seems to fit you best. They are just so similar, that I feel like complaints are sort of picky, but you know what you like.

Good luck. I really don't think you can go wrong either way.

-N