Double experiences gain by default all the time. I think no other benefits on Silan I can remember*
* Some later missions are (also) located on Silan and it needs a subscribed account to participate because of mission sub-tasks requirements, but not your case and it is more just a relation with the region
* Some later missions are (also) located on Silan and it needs a subscribed account to participate because of mission sub-tasks requirements, but not your case and it is more just a relation with the region