This was a satisfying read for me personally, since I am an introvert and it was so nice to read flattering things about my personality type. It was also good to feel like at least someone, somewhere, understood what I am generally about, that my preference for one-on-one interaction on maybe a less-than-regular basis doesn't mean that I'm "anti-social" or that I don't like people or anything like that.
That said, it is a pop science book, meant for a general audience and not supposed to stand up to serious scholarly analysis. Obviously that kind of approach has certain issues and a lot of the more negative reviews I've seen seem to ignore that fact. If you're not into pop science generally or if you know a TON about psychology and current research, maybe you wouldn't enjoy this book as much as I did. If you like straightforward, non-jargon loaded presentations of this type of information, it's a very good book.
The one thing I did find annoying, although I know other books do it too--when she would write about something, and then put something like: (I talk more about [blah blah blah] in chapter [X]!). It felt like she was trying to sell me her book when I was already in the middle of it, and that was off-putting since I was planning on finishing the whole thing, I would've found out what those chapters were about when I got to them. Do other people not finish books unless they have a preview of what the rest of it is about every once in a while? I seriously don't get it.