Yes.
The chapter on why the Bible does NOT mandate door to door field service (as practiced by JW's today) is worth the read alone. He lays out the facts in such a simple, clear manner that I don't see how any JW could possibly counter it. And I absolutely LOVED the chapter on logical fallacies and how the Watchtower publications employ them. As a born in cult member, I can honestly say I was never trained to think critically so that chapter was a breath of fresh air.
I am a former Christian, now agnostic. The purpose of ISOCF isn't really to convert you to being a Christian; it kind of assumes you already believe in the Bible. ISOCF is more about how the Watchtower organization oversteps what the Bible says and adds unnecessary baggage to one's belief system. To achieve this goal Ray naturally has to do a lot of "debunking" work, which he does skillfully and without a trace of antagonism.
Even though ISOCF is JW-centric, Ray still brings out a lot of very interesting principles that apply to other religions and secular organizations. For example, he discusses at length a recurring pattern throughout history: As an organization grows larger, regardless of what its original purpose might have been, the number one priority will eventually become self-preservation, even if that means trampling its founding principles. Thought provoking stuff.