Been playing the Union against CSA-Athena, slight FOW advantage for AI, extra AI computational time, normal difficulty, normal aggressiveness. Am at the end of 1862, and here is my experience with version 1.11a.
I have marched into Bowling Green, Nashville, Memphis, and Atlanta without much resistance at all. The same cannot be said, however, for Forts Donelson/Henry. Athena was quite fixated on holding that position, even when (or perhaps especially when) that position became untenable by my taking Bowling Green and Nashville.
After I took Nashville, I came up against Donelson/Henry from the south, laying siege with a corps. Through my own carelessness, I failed to interdict CSA resupply via river to that position. This turned out to be good for me, however, as freshly arrived CSA troops would sortie out of Donelson/Henry every other turn to try to break the siege. They always failed, and the result was a Verdun-like meatgrinder for the CSA. Maybe that's why Athena didn't have any troops to defend Memphis and Atlanta.
The story in the east was different and fascinating. Joe Hooker and the AotP managed to take Richmond. Then Athena did something amazing: she sent Bobby Lee with 25,000 on an end-around to take Harper's Ferry and (presumably) other points north. My 8,000 troops there, heavily entrenched with Gatling guns, managed to stop Lee long enough for me to detach my best corps from the AotP and chase him down. My corps under Hamilton gave Lee quite a thorough beating, but then my remaining troop strength at Richmond wasn't strong enough to hold that position.
Losing Richmond meant retreating to Manassas and Alexandria to rebuild during winter. During harsh weather, Lee came after me twice with devastating losses for the CSA--something like ten-to-one casualties in my favor. Does Athena respect bad weather as she should? Oh, and I have captured lots of CSA supply wagons; thinking of how expensive those things are, could Athena be more careful?
Having a great time! Fabulous game!