With XEB1004 pack (two XE104) I did contact the Freebox (in my living room on the 3rd floor) with my PowerBook in the cellar, 4 floors below, with a measured flow rate exceeds 75% of nominal.
Fan of Netgear products for several years, I am now convinced of the effectiveness of CPL Netgear.
It's really, absolutely "Plug and Play". No adjustment or manipulation to achieve.