Interesting; I did not realize, or had forgotten, that HTM had a prayerbook. I have to confess, I don’t like the older version of the Jordanville book that much (it is available online; I have read it, and it made me less than interested in buying the newer one). Jordanville publishes two volumes I much prefer, the Unabbreviated Horologion and A Psalter for Prayer. Looking at the table of contents for the HTM book however, it looks to me like it has a much more useful set of material.
My favorite EO prayerbook is the thoroughly unconventional Praying In the Orthodox Tradition, which provides beautiful prayers for the different hours extracted from a selection of disused priest’s prayers from various ancient manuscripts, such as the Barberini Codices that contain texts of our liturgy. This book would be of little use however to someone who was seeking to follow the traditional order of prayers and an akathist to prepare for Holy Communion (I have these prayers on my iPad in Orthodox Daily Prayers). I should probably get an HTM prayerbook however. It would be nice, and inexpensive, to acquire a library of these books, and write a comparison of their contents so people could figure out which prayer book was right for them. I am hoping my Marfan’s does not reach the point where I can’t handle printed books (so far it is mainly receipts and napkins).