Opus Dei has far too much power within the Roman Catholic Church. And it makes you wonder why such a small amount of people, who almost seem like a cult of their own within the religion, have so much sway over the church in general. It doesn't make very much sense.
Opus Dei allows for non-clergy practitioners to be members of the clergy. It is a representation of the people within the church. Membership and duties are still a bit of a mystery, as is much of the workings of the church. Some people within the organization must operate with anonymity in order to maintain order within the organization. It is this secrecy that raises doubt of its purpose. The Opus Dei has no more power than the church itself, and the church only has the power granted it by its followers and God.
Opus Dei does a lot of good work, and they have been unfairly maligned in the media. There have been a lot of sensationalist stories in the media that represent fictional accounts of the organization rather than the actual reality. The church really has little power beyond their charitable reach.
Opus Dei is a sect that is a subdivision of the Roman Catholic Church, but they do not have far too much power in the Catholic Church. The Opus Dei sect got a lot of exposure due to the Dan Brown series of books, but the visibility isn't reflective of influence.
No, this section of the church does not have to much power, and they use the power that they do have to do some good things for the church as a whole. The pope is the head of the Catholic church, so he has more power than anyone, but he is good.