I smile when I read all the survey results about what law department attorneys look for in outside counsel (See my post of Oct. 22, 2008: law firm attributes for selection with 12 references.). In the abstract, anyone can reel off desiderata.
The nitty-gritty chore, however, of rating a specific firm too often gets shunted aside or done poorly (See my post of Nov. 16, 2005: evaluations of law firms with 9 references; and Nov. 6, 2009: law firm assessments with 19 references.).