This is one of the earliest primary sources by a Christian woman, and I picked it up since I was interested in the voyage she took to see many pertinent Old Testament sites (the first half of the diary) as well as her experience of liturgy in Jerusalem during Lent and the Easter season (the second half of the diary). I did enjoy this, and found the description of the liturgies especially interesting. Let's just say, they were very hard-core compared to what you would see today in an average church during these seasons!
That said, it was often hard to visualize what was going on - as it is apparent in the (extensive) academic notes and introduction, many of the details are disputed, including the dating of this voyage, the locations of nearly all of these Old Testament sites that she visited, the path she took, and even her specific identity. The second half with the liturgies is easier to grasp since the sites within Jerusalem are known, but I personally found them hard to keep track of - there is a lot of moving between the various churches in and around Jerusalem for the various services. These sites are known, so it would have been helpful for me to see a map of those with a legend of which church was on which site, since they all have Latin or Greek names (Martyrium, Anastasis, Imbomon, Eleona, Sion, etc.)
Overall, I do recommend reading this for a glimpse into early Christian life, especially their liturgical prayer life; but this book (at least my edition, part of the Ancient Christian Writers series) is very academic so it takes some work to get through the introduction and the notes. If you're not an academic theologian, you may want to just read the text and skip all the notes and the introduction, just keeping in mind that there are many debates still happening about various things mentioned (or not) in Egeria's diary.