Thanks in large part to my productive Memorial Day weekend, I'm done with the first round of revisions on my second novel! I estimate that I changed about 30% of the text during the editing process. A whole new chapter was written from scratch, and large parts of three other chapters were re-written. I also resolved a plot problem that nagged me when I wrote the first draft. In the end, I believe that this second draft is significantly better than the first.
Now comes the hard part. The easy fixes have been made to the manuscript. Every round of editing from here on will only result in minor (albeit necessary in many cases) changes. The book will never be perfect, but at some point, I will have to decide that it is good enough to hand to beta readers. When they provide me with feedback, I'll undoubtedly revise the book some more until I deem it good enough to be published. Like many authors, I don't believe that I'll ever achieve perfection, but the question is how good is good enough.
But I don't have to worry about that for another few weeks. Now it's time to start the second round of revisions.