I observed one minor thing. Profile info is not shared among SE. While reputation should obviously not be shared, the location and the website should. For example, on Area51 I result to be in Tokyo, while on SO I am in the Netherlands.
Now, it may be claimed that I'm probably the only programmer who changes country every year since 10 years (and I'm still not done), but I still claim it as a technical inaccuracy (again, minor. I mean... SE is a technological jewel).