I just finished Aeoss Affair too. I found missions really confusing from the start, so I changed my difficulty to easy.
Story-wise, I wasn't convinced. This campaign pretends you are defending a remote area while the GTVA is fighting against the Second Incursion so they won't send much help your way. But until the arrival of the Sathanas fleet, you've got a stronger Shivan presence in Aeoss that in the Nebula theater.
Shivans even throw a Sathanas at you, and when command fails to track it, they just go "it'll be back, don't worry"
The campaign not only uses Myrmidons as bombers, but it uses for everything. That is not cool, I like variety.
There are good ideas in there, like the mission were you have to activate the satellites (which were difficult to find as hell) and
the mission where you have to protect the kamikaze ships to destroy the Sathanas.
I did appreciate the tons of bonus objectives which were properly included in the mission debriefing. I like that
. However, mission briefings and debriefings were generally odd.
So, in the end, I didn't like this campaign much. Maybe I should play it for the challenge at higher difficulties but I can't find the will to do it if the story is not compelling.