This is pretty good overall, nice terrain, decent variety of counters, plays smoothly, but both I and two friends have found that it's too easy for a single unit to slip through the lines and b*gger about with supply in a most unWWIlike fashion. I know the official answer is to adjust our strategy so that it doesn't happen, but I think this game would benefit hugely from small garrisons in all the cities and towns (not mines, etc). Maybe with the ability to move one hex out of the way if the location needs defending by a full corps, or if that's too tricky the garrisons could be disbanded when the front lines get close.
I just don't believe that a few thousand cavalry, hundreds of miles from their supplies, could operate like that in WWI Europe. It's not the Indian Plains Wars.
Another older WWI game, Commander The Great War, does have this feature and it prevents exactly this.
European cities of a size to be represented at this strategic level would have their own militias, old veterans, angry citizens, solders on leave or convalescing, training, en route to somewhere else, etc. The handful of Detachments available to all sides don't fulfil this role.
Or, at the very least, the ZoCs in this game should be made far more 'sticky'.
I'm not so bothered about the Middle East, or maybe even the Caucasus, but seeing a depleted French cavalry corps galloping into Aachen just doesn't feel right to us.
Welcome any feedback.