A good, engaging textbook. I particularly liked Ozment's overview of later medieval thought, theological, philosophical, and political. A subject like that can be difficult to cover in a textbook due to its technicality, but this is a nice balance of clear explanation, the occasional in-depth case study, and plenty of excerpts from primary sources. More textbooks should go that route, I think.
I also liked the choice of time frame, 1250-1550. Most books on intellectual thought would either go late medieval or Reformation, but Ozment decides to go for both and it really adds an originality to his work. I could have done with a little more interweaving of the two halves, but the fact that both of them are there allows him to demonstrate how the Reformation managed to be a shocking, traumatic moment for those who lived through it, but also a somewhat unsurprising development in retrospect, given the general trends of late medieval thought.
My only slight qualm is that I think he's a bit too hard on late medieval Catholicism. Don't get me wrong, a lot of it was kind of a disaster - but it was also a disaster that had been going on for a while. People had been complaining about corruption, clerical wealth, uneducated priests, and more for centuries before the Reformation, so it makes Ozment's claim that the Reformation sprung out of a general sense of spiritual repression a bit unconvincing (or at least underdeveloped). Still a very good textbook, though.
Just as a heads up, since this is a textbook: there are certain parts that may be somewhat slow going if you don't have any background in theology. The majority of it is very accessible and readable, but if you don't have any background in the subject you'll occasionally need some patience and a trip over to Google. It's worth it, though - this sort of mixture of clarity and depth is hard to find.