Von Balthasar wrote some great things, particularly about the Church. I liked two of them, Heart of the World and The Office of Peter, in particular.
I don't care much for the visionary, Adrienne Speyer, who was his inspiration for some of his more radical ideas, though. One of the problems with von Balthasar is that he moves back and forth between being a solid (and extremely wordy and detailed!) German theologian and being a mystic. There is the famous phrase that mysticism "begins in mist and ends in schism," and it is certainly true that some of his more "mystical" things may not be great doctrinal expressions. But many of his other works are really worth reading.
I have only read the Threefold Garland, but I was impressed.
I've read a couple of books of Adrienne von Speyr's, and they were interesting. However, they really didn't work for me, and ended up donated to the homeschool association book exchange or the parish used book sale.
Some writers, I just say, "Huh?" and she's one of them.