DxOMark does a good job (not perfect; I wish they did a better job of getting things reviewed sooner) providing some basic benchmarking on cameras and lenses. Some people seem to think that the top-line number their reviews produce, especially on cameras, are the final word on how good a camera is.
It isn't, but it does provide some nice data on some parts of the camera. For a digital camera, there's no doubt that the sensor is the heart and soul of the device. If the sensor is no good, the camera certainly won't be, either.
It might be the sine qua non of the device, but it isn't the totality.
Also, just looking at the top-line number can be misleading as well.
I learned this about when I got my D4. It was cool when it came up as number one, and a bit surprising when it fell out almost immediately (with the introduction of the D800). But the high-ISO numbers were a bit misleading on the D800, I think. While I occasionally wish that I had the extra color depth or dynamic range, I'm mostly happy because of the better ISO performance of the D4.
But wait, you say, they were rated almost identically there. Well, there's a bit of a story there, and it mostly comes down to dynamic range. The D800 is better at 100 ISO, and maybe at 200 (can't remember), but gets significantly worse after that. Given that I take a lot of indoor shots of my kids, I frequently end up shooting higher than that, so I largely come out ahead.
Plus, I like the way the D4 handles, better; it's very nicely balanced and the controls are excellent.
But, of course, there's still the money issue.
Anyway, I'm getting badly sidetracked. The points are that a) there's a lot more to a camera than DxOMark score and b) there's a lot more to their benchmarks than the top-line number.
So, now that I've pointed out my own experience with finding that out, I wanted to point people to a long article that takes a much closer look at their reviews. It's on an excellent site called Luminous Landscape and gives a lot of good information.
So before you buy a camera based on a DxOMark review, you should read the article to help you interpret the numbers. You'll be glad you did.