I've read most of Cardinal Ratzinger's work. It's very impressive. Evangelicals and other Protestants might want to look at his early work, "The Meaning of Christian Brotherhood," which was well received by Protestant theologians at the time.
The Cardinal is especially strong on ecclesiology, the theology of the Church, which suprisingly was almost undeveloped until recent times.
I agree with him about the Assisi meetings, and I imagine most serious Protestants would also agree. You don't bring serious Christians together by trying to water down or gloss over their faith. Evangelicals will find that they are better off with a strong Catholic Church, and Catholics are better off too when Evangelicals remain faithful. Most of the problems in our American culture have arisen because the "mainstream" churches have betrayed their trust.
As a member of the Evangelical Covenant with children receiving a Catholic education, I say Amen, with a bump.