As a user, I confess to using lists like the EAL and iaiparis just to drum up names, and more recently ArbitralWomen. Apart from any considerations of gender, AW allows searches based on an arbitrator's legal expertise (common law, civil law, Islamic law, and "European law") as a separate category from Legal System of expertise (country of qualification). For example, if you want to appoint an arbitrator who is a UK national but has legal expertise in the civil law (search result of three listed) or a citizen of France with expertise in the common law (one listed). You can't do searches like that in either EAL or iaiparis.

Michael McIlwrath, Global Chief Litigation Counsel at GE
(message on a list-serve dated 25 February 2015)