Performance
Getting down to the nitty-gritty, first off let me say that I immensely enjoyed using the 850 SW over the past week while I was on vacation. It's been a handy companion both above and below sea level. I’ll start off with its water-resistant capabilities as this is the first time I’ve used a camera underwater without a specially designed casing.
You can’t expect to get brilliant images of course, but the 850 SW will give you some pretty good ones. There are a few underwater modes you can select for different purposes. I didn’t want to show you a picture of something in a bucket of water so this is what I saw on the ocean floor at a depth of about five feet.
Macro shots come out pretty neat, and with the Super Macro mode you can quite literally get up close and personal with your subject. The images may have a bit of noise on close inspection, but are nevertheless quite good. All the same, you will need to have a steady hand if you wish to avoid blurred images.
Macro
SuperMacro
Here’s an example of what an image in motion (with colors and quite far away) looks like with 3x zoom. The reason the image may appear a bit a dull is due to the overcast sky.
If you happen to be behind glass and need a good image you obviously don’t want the flash going off, but the 850 SW has a separate setting for images behind glass. Here’s an example. Again the weather was a bit dull, but on closer inspection you will notice a slight purple tinge to darker parts of the image with a bit of a painted effect. But the image is still quite decent. I mean, how many of us are going to zoom in to take a close look at the details of the picture, right? But it’d good to know for those of us who are sticklers for detail.
In sports mode, even high-speed objects look quite good and the details quite evident. Thankfully or not (depending on the effect you want) the images seem to be blurred in all the right places.
I just bought one, the orange color, and within 1 month it got the tiniest dent, you cant even feel it, it is more like a scratch, and it caused one of the airtight components to slightly move and water can seep it. i guess it was a waste of 300$. 
