"Interesting". Did I mention "interesting"? A good history oughta be interesting. No dull history narrative, please; interesting. Fascinating would do, too. :o)
To your other point, I accept that the structural style of "Salamanca 1812" may not suit every historical challenge (although it has the merits of allowing the reader to skip past the analytical chunks that are too detailed for the reader's taste; but, one may wonder, why read a battle study if the reader is not interested in the detail of how it came to be?!), but I was championing the honest-dealing that underpinned the structural choice. I found that being open-handed with the reader about where historical evidence supported a nifty narrative, and where it left narrative hanging in the winds of potential invention (or good creative reconstruction), made for interesting history--it got the reader involved with history itself (raising central issues such as, just what is history and how and why do we think so?).
Pondering - Howie