I have to admit, I find the enneagram to be problematic in some ways, but I set that aside, and am reviewing this book on its own merits, apart from the merits of the enneagram itself.
There are certainly some good things to glean from this book. Ms. Stabile very quickly cuts to the heart of what drive each enneagram type--and beautifully illustrates this with very accessible and relatable anecdotal stories for each type. I also really appreciated that she showed the positive and negative issues with each type interacting--without ever insinuating that some types just can't have relationships. In fact, I found her overall positive approach to be very interesting and refreshing.
I think Ms. Stabile's weakness lies in her lack of objectivity. There were inaccuracies in her type descriptions, and I strongly suspect that those are due to her own bias based on personal interactions with these types. For example, she describes 5s as very organized planners, who are convergent thinkers. I suspect she may have come to these conclusions based on her personal, close relationships with 5s in her life (she mentions that both her mother and her close friend are 5s). However, if the 5 in question is a "P" on the MBTI, they will value spontaneity and divergent thinking, while eschewing planning and organization. Another example would be her very specific, yet not accurate for most, description of 2s--she herself being a 2 has, I think, heavily influenced and slightly corrupted the description of them.
All in all, I found The Path Between Us to be an enjoyable, useful, and accessible read, filled with helpful nuggets of wisdom for examining yourself and relationships, without the common personality pitfall self-indulgent navel gazing.