Tina:
I don't have the 850, but I do own a 790SW - last year's model. It is an adequate camera - not the best. But it can hold up to some punishment. I do a lot of running, so was looking for something to stand up to the shock of constant jarring from miles and miles of running, and from the moisture that often accompanies running - especially when it's me.
I looked at three cameras, and choose the Olympus becuause of it's durability. Here's a short write up on my blog:
Olympus 790SW.
The camera is not a great low light camera, but does okay in good lighting. Here's an example from
low light conditions (including some video from the camera), and some better quaity stuff from my recent
Run to the Top of Baldy. One thing to keep in mind - the camera is compact enough that I "ran" to the top of Baldy with the camera in my palm the whole way.