Got my IXUS 860 (aka SD870) today...

To set the scene, this is an upgrade to an S1 IS and my primary use is casual p&s with no delusions of grandeur about IQ.

First reaction on power up is "Wow - this is fast". After a few hours of playing, I'm impressed at how quick and responsive everything is. All my initial testing has taken place at night in low artificial light and I'm really pleased with the performance. The half-pressed button focus is really fast and AiAF mode gives essentially instant shots.

The button layout is superb! Coupled with the fast response time, changing the settings is really easy. I felt that the main dial was a bit small at first and had a bit of trouble using my thumb to control it, but I got used to using my thumbnail instead and it seems ok.

As mentioned before, I've only taken shots in low artificial light. Compared to the S1 IS, it is excellent in low light. I was really worried about the high ISO images, but they are quite acceptable under the circumstances. ISO400 is much better than I expected. Even some of the ISO1600 shots I've tried are OK.

After 729 shots on the initial battery charge, I've given up trying to flatten the battery! Of the 1st 300 shots, I'd guess half were taken with the flash. I then put the camera into continuous mode with the flash on and was able to take 20 shots in about 30 seconds before the camera stalled to charge up the flash. The next 300 or so shots were taken in continuous mode - it's also much faster than the listed 1.3fps if light and focus are good.

IQ from my low light testing has generally been great when viewing the jpegs on my 21" computer screen. At 1:1 I can start to see some of the compromises in IQ. Zooming in shows all of the sins of the camera's onboard processor. Barrel distortion at full wide angle is really obvious when the subject is close.

I'm intrigued by the ability to optical zoom to 7.8x when using 1600x1200 images. It seems to work really well. The digital macro and digital tele functions also seem to work really well - I'm yet to figure out exactly what it going on here, but the images look great.

The movie mode is far, far better than the S1 IS. Bumping up the exposure in low light, or using the night scene mode gave stunning results. Focus is lightning fast. The digital zoom at 4x in movie mode was pretty woefull however.

All in all, I'm stunned with how good this camera is. I base this statement on the fact that the camera's features are more important to me than the IQ. For my needs, the images look great!

Mark