Yakovlev is president of the International Democracy Foundation in Moscow and chair of Russia's Presidential Commission for the Rehabilitation of Victims of Political Repression. He's also a former Politburo member with amazing access.
The book does a good job pointing out the attrocities of the Soviets, and uses many archival citations, while naming names. It shows Lenin for the terrorist he was, and how Stalin just continued his policies.
Does it build on and verify Conquest, Sozhenitzn et al, or is there entirely new unknown matter?
BTW, here's a version of my soon to be book cover.