I’m not a member, but my spiritual director is an Opus Dei priest.
Like anything new, I had my suspicions. I think this is a natural response. Escriva may be canonized, but that doesn’t mean individual members of his movement can’t be pushy, fanatical, or downright elitist. You should never allow yourself to be influenced by a person or an organization before you’ve tested the spirits, so to speak. And often times you may simply not like an organization because you clash with some other person’s attitudes or personality. This is human nature.
I think what scares people about Opus Dei is that they want to focus on your entire life, including your professional life, and your family life. In our society, people want you to separate your professional life from your personal life. Its almost the mantra of relativism. They want you to leave your faith at home, and exclude it from conversations at the office, in our hospitals, in our governments.
To add insult to injury, they also encourage their members to evangelize!!!

God forbid that any religious person seek to share the gospel! This fact alone automatically puts you in the position of a fanatic in popular opinion.
But my experience so far is that Opus Dei truly wants you to be fully Catholic. In terms of spiritual direction, that means the application of doctrine to my life. My spiritual director is a spiritual doctors, so to speak. He finds places where my life is not in conformity with Catholic teaching, and he points it out to me, suggest ways in which I can improve, and grow closer to God. Its not judgemental, but more of a conversation with a friend. He makes no commands.
I started going to him in November, and since then I’ve seen him every month, and its been good.
I also started going to their monthly recollections. Its like a mini retreat once a month. Its really good because they can say things that you rarely hear during a homily, mostly because a homily is not the appropriate place for comprehensive catechises and moral formation.
It was a little intimidating at first because many of the members are successful business men, some are polititians, or ex-politicians. Some a doctors or lawyers, or phychiatrists, or psychologists. I found out that I knew many of these men in other contexts and never knew they were part of Opus Dei.
Anyway. These are my thoughts about it, for what its worth.
God bless,
Ut
P.S. Here are my thoughts before I started seeing the spiritual director and going to recollections from last year in June.
forums.catholic-questions.org/showthread.php?t=245197&page=3&highlight=Opus+Dei
If you read them, you will see some big changes in my attitude. Most of my fears expressed in that thread have been totally dispelled by my positive experiences with them since then, and up until now.