I just finished volume I of Previté-Orton. It was at times tedious, but often very instructive - which, admittedly, wasn't too hard to achieve given my near-total ignorance of the subject matter.
Perhaps the most interesting part of the book was the overview of the Byzantine Empire, and particularly its remarkable stand for a century against Muslim invaders at a time when it was subject to attack literally from all sides. But the material relating to the period from 1000-1200 in Europe was also good.
One of the difficulties for me - as a total neophyte on the topic - is judging whether the author is a partisan. On balance, I guess I'd have to say that I'm inclined to say that P-O made a good effort to be fair to his subject matter, an opinion I hold on the basis of his coverage of things about which I knew at least something.
It seemed at times that the focus of the book was almost entirely upon military and political stuff, but an author has to make choices (particularly when the book is really a distillation of an eight-volume work on the same subject!). And to be fair, he did invest more space on other topics later in the book.
On the whole I'd say that this seems to be a good introduction to medieval history, and I commend it to you if you're looking for one.