I used the 5700 for an entire day + a small photo shoot a week later, taking photos of Motocross riders for work. It was on the auto mode for every picture. The photos during the day were amazing. Color, clarity, all perfect.
But.....when the sun started to go down, the flash needed to be used for the camera to autofocus. It was still pretty bright outside, most cameras wouldn't need flash at this point. And unfortunately, the flash is the camera's weakest feature. Focusing rarely occured properly in these low-lit conditions, even when the subject was center-frame. All subjects were no further than 12ft away. Little known to me at the time, the camera's effective flash range is about 9 feet when zoomed in full telephoto. That is extremely pathetic. The camera would focus on objects in the background. To make matters a little worse, it seems to have similar problems if your subject is standing in the shade and the background is brighter than the subject. It wants to focus on the bright background.
I'm sure if I knew how to play with the different autofocus modes, I could've fixed the problem to a large degree. I wasn't very familiar with the camera at the time. However, most of the high-end digicams out there work fine in these conditions with their default settings.
Here's examples of a 5700. The first shot is near sunset, the second shot is a bright day with the subject standing in the shade of a tree. The first shot is using the flash, zoomed in from about 10 feet away. The second shot is not using a flash, zoomed in from about the same distance.
After using this camera a bit, I decided it wasn't for me. I had an old Olympus D-600L that had low-light autofocusing problems and it drove me mad. The 8X optical zoom on the 5700 was awesome, but if I couldn't use it in low-light conditions from a decent range, I didn't see the point. There are other issues that kept me from buying it. It has a pretty slow save-to-card time, which was driving me nuts when using it. Expect to wait some time in-between shots at full resolution. Also, I really like cameras that accept standard AA batteries. NiMH rechargeables are dirt-cheap, and in a pinch you can just throw regular batteries in. The 5700 uses a proprietary battery from Nikon, and will run you about $25 for a spare.
When I read about the Olympus C-5050Z, it seemed like everything I have ever wanted in a digital camera, except it only had a 3X optical zoom. After reading reviews all over the web and looking at the digicam article in Consumer Reports, it started to become obvious this was the camera for me. Being $300 less than the 5700 didn't hurt either. Anyhow, the big deal-clincher that convinced me to finally go out and spend the cash was the fact that Olympus makes an underwater housing for this camera for $200. I love to take photos of my SCUBA trips, but the only thing I had was a Sealife Reefmaster camera. After having owned the camera for about two weeks now, I can honestly say its amazing. Color and clarity are on-par with the 5700, and it has amazing low-light focusing.
For anyone looking at 5MP digicams, be sure to check out other options besides the Nikon 5700. Just because it's the most expensive consumer camera out there at the moment, it doesn't necessarily mean its the best at everything. Sorry if I sound like a commercial here, I just though my experience researching and using 5MP digicams may come in handy to someone.