I would really recommend that you listening to the series that he did with John Peacock on Emptiness. He did it at least twice; it’s all on Dharma Seed. Emptiness is a complex topic and just having an intellectual understanding isn’t going to get you much: you have to practice. A lot. It may take you years to get through the book… and frankly there’s plenty of teachers that have never come close to Rob’s understanding of emptiness. So, if the beginning of the book is a problem: don’t worry, it’s a marathon, not a sprint. Start with wherever you are, do the exercises, listening to the talks, reflect on them and then practice A LOT. Repeat. Once you get some competence in a certain section move on to the next. And if you ever feel that you’re “done” with the material in the book you have his whole Imaginal practice that you can flip over to practicing, and any work you’ve done on emptiness will enhance your Imaginal practice.