I like your coverage of European comics. I think they are too often neglected on news/reviews sites.
My first Spirou & Fantasio was also the "In New York" book. I corresponded with Cinebook and it sounds as though they'll be doing the Franquin Spirous at some point in the near future, and that has me excited. From everything I've heard, Franquin is the high water mark on the title.
Just checked Cinebook's website. They're not even publishing the Tome & Janry run in order?
And pardon the following rant/explanation as I'm French Canadian and have thus read most of the Spirou series.
I agree that the Franquin run, especially the second half, is just amazing.
Tome & Janry's first book (#33 actually) VIRUS is one of the best, that was followed by Down Under, then Qui Arrêtera Cyanure? (Who Can Stop Cyanide?).
If they haven't done the Franquin run then I can understand skipping the next two (L'Horloger De La Comète "The Comet's Clockmaker"(???) and Le Réveil Du Z "Awakening of the Z" because it requires knowledge of Franquin villain Zorglub among other things.
The next one was just a collection of random short stories.
New York (#39) is good, but I didn't think much of the two-parter Running Scared/Valley Of Exiles, and the 3 after that were even less interesting.
Luna Fatale #45 was a long due return to form, but that didn't last long.
Their final volume -which took YEARS to come out if I remember right- Machine Qui Rêve ("Machine That Dreams") was.... weird I guess. It was done in a more realistic style (or at least less cartoony) and while not a bad story in itself, it just didn't really work as a part of that run. And it somehow stunted the series for a few more years until the next creative team finally came along and now they are back on a 'regular' yearly schedule, but I haven't read most of those.
There is also a series of non-canon "Elseworld-style" one shot books by various creator doing their take on Spirou and Fantasio (some being REALLY out there, like Spirou and Fantasio versus Nazis during German occupation of France in WW2!) that are worth checking out, but who knows if Cinebook will ever get to those. Machine Qui Rêve might have fit better in this series now that I think about it.