@ Randy, excellent Review - thanks!
@ Bill, it's a different approach to the subject area. Osprey are useful, IMO, as more-detailed background reading and (usually) have a first-class text and some nicely executed color plates. However, Concord, in their series' do tend to give more in the sense of contemporary images and also some impressive color plates. Concord are more an illustrated series and apart from 2-3 pages of background, do tend to let the captions tell the story.
Unfortunately, in some of their books, it's the Editing which lets them down a bit. They also tend to go for more (and smaller) images which sometimes can be quite frustrating. although the quality of their images HAS improved in the last few years, there a still a percentage of 'muddy' images. Another tendency they have (and this is NOT the fault of their Authors) but rather the commissioning Editors, is to cover a 4-5 year period in 1 (sometimes 2) volumes. There IS a growing tendency for publishers such as
Firefly Books (formerly the Factory Publishing) to do books which cover aspects of a specific campaign. This makes for having to buy more books, but, in the end, it's worth it...