The below excerpt on waiving your right to review law school recommendation letters (and letters of recommendation in a nutshell) is from A Guide to Law School Recommendations.
Applicants often ask me whether they should waive their right to see letters of recommendation. My response—and that of most of my colleagues—is an unqualified yes. Naturally, admissions officers are inclined to put more stock in a letter that they know was written without concern about how you might react to it if you pulled it from your file one day. Professors and other recommenders may be inhibited if you haven’t executed the waiver or see it as a negative. So, there are definite downsides to failing to execute the waiver.
However, there shouldn’t be any significant risks in signing away that right: you’re choosing the people who will submit letters of recommendation and talking with them about those letters in advance. If you don’t trust them to write letters you can submit without peeking, you should probably be reconsidering your list of recommenders rather than attempting to control the situation by retaining your right to review the letters.
Letters of Recommendation in a Nutshell
– Choose recommenders based on how well they know you, how willing they’ll be to invest in writing an effective letter and how they mix with your other recommenders, not just the impressiveness of their credentials.
– Avoid blatant plays for “big name” recommenders.
– Try to balance your recommenders so that your letters aren’t substantially similar—use the opportunity to show different strengths or how your strengths play out in different contexts.
– Make the process as easy as possible for your recommenders; give them everything they’ll need in one place and use that opportunity to educate them about what makes an effective letter of recommendation.
– An effective letter of recommendation illustrates key points about you and provides information about the writer’s experience with you and basis for assessing and comparing you to others.
– The letter should generally not be more than one single-spaced page.