We do not have any direct studies of the Experian National Equivalency score vs. the FICO score, however judging by the feedback from many of our users, the score is relatively accurate. Both scores use the same range, and the Experian National Equivalency score is in correlation with the FICO in terms of the direction your FICO score moves.
CFPB states 4 out of 5 consumers would receive a meaningful score compared to the scores that creditors use.
Here is a link:
Credit Sesame is a valuable tool. I also use it to keep tabs on my EX report, however I put no value into the scores that they post. I've never had my Creditsesame score within 50 points of my Fico score, and have been off as much as 87.