The US and UK sites do have different standards and criteria. However, we are currently working to bring all of the sites in line with one another so ratings are more consistent.
As PistonCupChampion said, though, we all have different opinions about what makes a good camera, or good product in general. While ratings are helpful for giving you a quick glimpse at whether you should consider a camera, they should not be the only thing you use to make your decision.
Read the reviews and you'll see there are some things that I might feel are bad or are not as good as you'd find on another camera, but don't matter to you. For example on this camera, I found the AF system when in Smart Auto picked the wrong subject too often and there's no option to override it. If you do most of your shooting in Program Auto, though, you can switch to Center AF and the problem goes away. It's really up to you if that's a deal breaker. It's not something that keeps me from recommending this camera, but something that did change my performance rating for it, which in turn lowered the overall rating.