It is a nice game if you like games like Ruse and Wargames series.
You have reinforcement points to call in units which is more realistic but also harder since you have to think about your decisions.
There is a common problem, if you install the both WiC games (WiC and WiC SA) then the game will not launch campaign. to fix that simply uninstall the SA.
You don't need to have original game to play SA since SA is stand alone.
The game some how is a reminder of Generals even though there is no base management.
It is a nice game worth the money.

Update.
Now I have finished the game, this is definitely worth every penny.
The campaign was really good, the weapons at your disposal varied and the missions fun.
The story was heart warming and sad at the same time and that made it even better.
If you are a big military strategy fan like my self and have been having a hard time for a long time to play a good one this is for you