I'm inclined to agree with you. It always seems to me like he has a lot of good stuff to say (both with his fiction and non-fiction), but rarely communicates it very well. However, I recently read Mere Christianity and found it to be one of the best books I have ever read. I was a little disappointed to find that The Four Loves wasn't quite of the same quality, although many good points are still made. The Screwtape Letters is also very good and definitely his best fictional work as far as I have read.