I do know he had disagreements with the current Pope Benedict over some things. I don’t remember what. I think Rahner was more focused on abstract ahistorical philosophy and theology while Ratzinger focused on what was called resourcement or something, meaning to go back to the sources, like the Church fathers, and build from them. Rahner is more ahistorical, while Ratzinger (Benedict XVI) emphasizes the historical aspect of God’s revelation to man. While reading Rahner, I would always supplement everything you read with study of the current Popes work. I had a horrible spritual director who was condescending to Popes Benedict XVI and John Paul II while he suggested Rahner. I later discovered he is not in tune with the magisterium much at all, and had to dump him. Always find out what a potential or current spiritual director thinks of the current Pope. I personally would never be able to listen to a spiritual director who downplays a current Pope, especially Benedict XVI, so make sure that your spiritual director is in line with the magisterium and the intentions of the Pope. I had a horrendous experience with my last spiritual director, and ended up having a lot of problems. I will never take spiritual direction from someone who thinks they know more or better than the current Pope. That’s my prerogative, but I think it is good advice. Just make sure he doesn’t have hostility towards the Pope, because I know that Rahner had some fundamental disagreements with Pope Benedict while he was a Cardinal over certain things.