c# - Is sa1200 All using directives must be placed inside the namespace (StyleCop) purely cosmetic?

sa1200 All using directives must be placed inside the namespace (StyleCop)

Is this just for code readibility or is there any actual advantage to doing so?
Does it help the GC somehow?

Answer

It definitely won't help with GC.

Here's the discussion about two styles:

http://blogs.msdn.com/abhinaba/archive/2006/08/21/709051.aspx

http://blogs.msdn.com/abhinaba/archive/2008/07/08/do-namespace-using-directives-affect-assembly-loading.aspx