Hi Bob E
Well, I cannot really comment on the quality of the Fokker D VII Aces book

; but I can on the others.
Norman's Sopwith Camel Aces book is really great, and IMHO you should get it. I count three of Harry Dempsey's profiles repeated from "American Aces of WWI" (Vaughn, Lussier, Kindley) and three subjects which also were profiled in ""British and Commonwealth Aces" (Frew's B6372, Rochford's D3417, and of course Barker's B6313) - However, Harry's profiles in the Sopwith Camel Aces book are far superior (frankly) to Mark Rolfe's in the British & Empire book. You'll get a good historical overview of many aces, and excerpts from Norman Franks' many interviews of various Camel pilots - good stuff !
The "Fighter Units" books aren't really new, but are very, very desireable. These were all part of the old Osprey/Airwar series of books (most of them on WW2) and were first published in 1978 or so. I remember the great joy with which I first read them back then; I was glad to see Osprey was re-publishing them to make them available to a new generation. The two German volumes were written by Alex Imrie, and the two British volumes by our own Alex Revell - and it just doesn't get any better than the two Alex's !! They are all seminal, very well-written basic histories of the development of the fighter forces, and superbly organized and illustrated. Though not as profile-heavy as the more recent aces series, each volume contains 8 color pages, with two in each volume devoted to a color five-view of a particular colorful machine. Each also contains four major side profiles of other significant aircraft, and scrap views of notable markings from about 6-9 other aircraft, or uniform details. One also gets a color view of a significant ground vehicle (I love the red Thornycroft van impressed by No. 5 Squadron as an ammo carrier, marked "The Worlds' Appetiser - H.P. Sauce" on the side, in "British Fighter Units 1914-1916"), and also three color paintings of figures in associated uniform and flying kit .
In short, these four books have been some of my most-loved 'bibles' and frequently-referenced titles over the years. Get 'em all. While many of the color profiles will look familiar, it's because other writers (like me

) have used them as sources for their own work in the years since these were published.
In the second German Fighter Units book, you'll note the light blue undersides of Buechner's Jasta 13 D.VII (the subject of a recent thread) - unless Osprey chooses to correct this, which I doubt :-/. Alex Imrie has since stated he based this on an erroneous recollection by
Rudolf Stark that all OAW D.VIIs had such undersides. Alex has stated that he was mistaken, and the undersides were in fact regular underside lozenge fabric. It's always those small mistakes that later rear up and bite the author !! Don't let that small mistake dissuade you - buy these books - at least that's my recommendation.
Greg VanWyngarden