Host advantage was easily noticeable on previous CoDs, but on BO (PS3) the host has a tendency to lag and sometimes freeze mid game for no apparent reason.
I think it has something to do with Theater Mode recording on the HOST's connection, I've noticed when it fails to migrate hosts you lose your recording of the match, I presume it's due to the hosts connection?
this is the most logical post i have seen regarding host lag,
i always suffer from host lag, my framerate drops so much too, i absolutely hate being host, its ****ed up my k/d
and i'm forever being selected as host even though i only have 3/4mb up.