Stay away from Opus Dei. It is not of God.
I have known several Novus Ordo Catholics who attended Opus Dei events. They were instructed that they had to obey their Opus Dei confessors under obedience. These Opus Dei confessors told them not to attend the SSPX or Resistance Masses. In fact, after being under Opus Dei guidance, they soon developed scrupulosity, and had more obediences placed upon them. It is a very controlling group.