Truth, the Whole Truth and Nothing But...: How Much Do You Think You Need to Know?

I recently watched the movie Revolutionary Road (trigger alert: infidelity!), in which Frank (Leonardo DiCaprio) confesses to his wife April (Kate Winslet) that he's "been with a girl a few times". While BWC members' responses range from "Who" to "When" to "Why"...most center on that last question. Frank attempts to answer by offering up the usual two-bit psychoanalysis of what might have driven him to have an affair, but April stops him short. "Not why did you do it," she says, but "why are you telling me?"
It's a fair question. She seems to not know nor suspect, though their marriage is fragile to say the least. Assuming Frank is honest in his desire to put his transgression behind him and to focus on his marriage, why did he tell her?
And, in hindsight, would you want to know? Or would you rather move forward together or apart without knowing the full truth of your relationship? Is that even possible?

Full Disclosure
If it's true that Tiger Woods is at a rehab center for sex addicts, one of the steps is full disclosure of his sexual acting out. In other words, the truth, the whole truth and nothing but the truth.
I was offered the same process or rather I was told that I would be participating in the same process – complete with his and hers therapists to support both of us during the disclosure session.
I opted out. It struck me that it was sounding more like an ambush than a disclosure session, though one could argue it's just a matter of perspective. Byt hat point, I had asked – and received answers for – my most pressing questions. I had been tested, thankfully negative, for STDs, including HIV.
I didn't want to know any more. I felt shell-shocked and completely overwhelmed.
Experts insist that the disclosure process isn't to ram unwanted details down the betrayed wife's throat, but rather to put both spouses on the same page, metaphorically, so that they can move forward in their relationship equipped with the same information. Honesty, they argue, is critical to a healthy marriage.
I agree...but I think the betrayed wife should hold the controls. She should be the one to determine the questions, decide the level of detail and even define a schedule.
What do you think? Did you want to hear everything? Or "just the facts, ma'am". Can too much information create more problems? Or, if something is held back, might it re-emerge at a later date and create more problems?