User blog comment:Legionwrex/How did Saren reach the Citadel?/@comment-1440333-20130507094740/@comment-2250460-20130507162241

The Beam in London was specifically designed to carry unprotected bodies to the Citadel which was right in orbit.

The Conduit was a miniature Mass Relay that travels across the galaxy. I think there is a difference between the two.