The iPad has become a formidable competitive weapon for law firms:

Quote from Fennemore Craig case study on Apple.com/business:

"If I didn’t have an iPad as a lawyer, I’d be at a major disadvantage,"

Quote from Virtual Strategy Magazine article: iPad® Harnessed by Law Firm to Sharpen Client Service

Now, legal materials live on a fleet of iPads that Fennemore Craig pre-loads and loans to clients and adversaries.  Communication with lawyers occurs instantly through built-in FaceTime or Skype apps.

My opinion:  The worry over what kind of laptop to buy is fading because of the domination of the ubiquitous iPad.  If you have not acquired iPads for every lawyer in your firm, at least provide them to a subgroup in exchange for some serious exploration as to how the iPad can assist in your substantive practices as well as your relationships with your clients.  Every day that passes is increasing the relevance of the iPad to your competitive position.