Islamic World in Ascendancy: From the Arab Conquests to the Siege of Vienna Book

It seems unfair to give this a bad rating, because it is unclear exactly what I am grading here. I did not read Goitein's five volume epic study of the Jewish community of medieval Egypt, and he clearly intended for his work to consist of all of those volumes. This is abridged, and maybe the abridgement is just bad? Then again, am I evaluating Lassner? He edited the five volumes down to one thick volume, and maybe that was kind of misguided, but it was his job, he had to do it. I'm sure I couldn't do a better job editing all that text down to one readable (well, somewhat readable) tome.
I think Goitien's study maybe should only exist as five books. It should be something that college libraries have on the shelf, and when you want to do some research you can explore all of his scholarship to your heart's content. Hardly anyone is going to check one of the volumes out and take it to the beach, but who cares? Again, this is just personal preference, but this abridgement did not work for my class at all because we were studying traders, primarily, and Lassner decided to cut almost all of the detailed trade correspondence in order to talk more about the structure of the community in Fustat/Cairo. Which, fine, I'm sure there are people who are more interested in that, but they can check out volume two of the whole set and I can check out volume one. As long as you have all the unabridged volumes. If you only have this I'm out of luck.
See what I mean? Anyway, I'm just still a little disappointed. Abridgements, man, you got to be careful with abridgements.