Here is a couple of articles I found that deal with the subject of Ad-aware vs Spybot S&D. The interesting thing is that almost nobody out there clearly prefers one to the other.
(esconder) Mantenha a sua Caixa de Mensagens limpa, Arquivando mensagens importantes e usando regularmente a opção "Apagar TODAS as Mensagens". (pauloaguia) (mostrar todas as dicas)