I too struggle with this issue. I feel that, for myself, I need to hear everything so I can then deal with it and put it behind me. It's like cauterizing an open wound. Hurts like he**, but in the end, there is less chance of infection. Also, if the spouse is unwilling to be open about it and learn from it, I think it makes it more possible to happen again.
In the book "After the Affair", it basically comes down to it needs to be the choice of the offended partner (not the offending partner). It should be their choice, but they then should be prepared to handle the information properly (calmly and supportively).
So, it's very much an individual choice.
TJ
Me45,H49 D24,S18 M26,T28 Bomb 3/19/08 Sep 6/23/08 EA/PA with Secretary 2007-8 3/2009 H moved in w/OW2 7/2009 Let him go w/Love. 8/2009 Legally Sep'd