I bought SOW Gettysburg when it was first released by NorbSoft and played it for a few months including a couple of online sessions with a friend. However I haven't played it for a couple of years and didn't purchase any of the additional civil war titles or SOW Waterloo.
The only reason I don't play any of the games in the SOW series is that they cannot be played by PBEM. I have been playing the Combat Mission series for years by PBEM which uses the WEGO system. Both players plot the movement and actions of their units followed by the resolution of one minute of game time.
In my opinion it is like a real time game broken down in to one minute segments. For civil war and napoleonic era games such as the ones in the SOW series I would increase the time segment to five minutes. Both players plot their actions and movement followed by the resolution of the next five minutes.
It is obviously much more convenient to be able to play a game by pbem and you can also view whatever parts of the battlefield in your line of sight using the replay of the segment.
I posted the question about adding pbem on the SOW Gettysburg forum years ago and the reply from the developers was that it was not being considered. It works very well in the Combat Mission series so I would definitely purchase more games in the SOW series if they do add PBEM.