I'm reading it now. I just began actually and I just finished Chapter 7. I like how he says that "a simple reaching out directly toward God is sufficient, without any cause but Himself." This directly reflects the thoughts of one of my favorite saints, Therese of Lisieux (the Little Flower) who wrote, "Prayer is, for me, an outburst from the heart; it is a simple glance darted upwards to Heaven..." (Story of a Soul, Chpt 10).
Have you read any of St. Teresa of Jesus of Avila's works (Interior Castle or The Way of Perfection)? IMO she discusses the same things the author of Cloud does but in a much clearer manner--I don't have to re-read her as much as I do the author of Cloud--then again, it could be the translation I am using.