Hi Madgamer
I will tell it[:D]:
WIA is what you need if you liked the AACW game system but found that game too big, time consuming and complex.
This game is easier to come into, and more playable as it comes with many small and medium sized scenarios (besides 3 big campaigns with variants) that can be finished on a couple of evenings.
But still is a very fun game that offers a lot of strategic possibilities and interesting command decisions: troops are few and North America is huge, so you can't be everywhere at every time and your decisions can have big impact.
WIA scenarios (even the biggest campaigns) have much less unit density than the ACW ones. Especially the French and Indian Wars ones.
It's a more intimate kind of game, where you will come to know by heart even the last Indian unit at your disposal.
There is no army/corps/division structure as this was something not "invented" by then. Just stacks.
WIA does not have "real" production as the ACW. It works different and is less complex. Mostly by historical events and with some buyable reinforcements.
There is no real economic part neither.
As the British/French you mostly depend of what the king wants to send you form Europe, based on historical events and influenced by you successes or defeats.
As the Americans your militias are free men that get raised and dissolved mostly as they see fit.
So to make them stay on the army instead of going home on winter you need to have high loyalty, control of the important towns and a good leader like Washington able to make them stick around and wield them form militia into continentals.
Even if the game engine on AACW and WIA is mostly the same, the feeling of the game is very different on my opinion.
Probably WIA will not be liked so much by monster games lovers like the players of WiTP.
Why don't you try the demo and see by yourself?
http://ageoddl.telechargement.fr/latest/WIA_Demo.zip
Regards