I read the American Presidents series biography of John Tyler and they quoted this book a lot, so I decided to check it out as it purported to be a biography of both John and Julia Tyler. This is a much more personal (versus political) biography, so I found it very interesting and fun. If you have a Nook (which I do), you can actually get it free. My caveat here is that this copy is obviously OCRed and so there a lot of "typos" that are actually scanner/OCR mistakes. But it is readable and I like free. In addition, the page numbers are off so you can't use the endnotes from another look (like that first biography) to find sources easily. But if you just want to read it, it is worth the price. I did enjoy the fact that this was much more personal and it really gave a nice glimpse into Tyler's family and personal lifestyle. This hit much more on his debt problems, his children and his marriages.
I actually also checked the book from the library and that does match page numbers and all, so if you were doing a research project that would probably be better.
In either case, this is a solid, in depth, look into Tyler's life that focuses more on his personality and lifestyle rather than political details. Politics is obviously covered, just not as in depth as other biographies.