I've read it a few times at different periods in my life, and just loved it - and benefited from it too

I bought myself the Experimental guide and did a lot of the meditations and exercises in there too - some of them I skipped as well

I read all of the other books that came afterward - the only one that I didn't enjoy was the last one (I think the 13th insight? Not sure, now it was so long ago! - It was the Secrets Of The Shambalah)....

The personalities also stuck with me - and also about what personalities your parents were and why you are the one you are... very interesting stuff!