Opposing fronts is better than the original.
In the American campaign nothing has changed, same missions, same units.
In the British campaign their are a lot new units, first of all, the motors must be stationed then mobile. Also, the command stations, such as the HQ are now mobile. Also, new rifle units can deploy a sniper to take care of a any problems you come out with while playing. Also, you can build stationary howitzers with the British engineers.
In the German campaign, It is totally different concept. Instead of the regular German forces as in the regular CoH, this is a totally new German force. In this campaign you can capture points with a motorcycle carrier. Also the units are only 3 for an infantry, but you can raise the infantry up to 4 per unit. Also you can have assault rifle units, panzershrek units, and long range rifle units. You also can have a tank destroyer, panzer, and multiple halftracks.
Multiplayer, Is way more better than the regular CoH, it gives new maps, also it gives you more time to play with the British units and the new German units. But there is some lag that sometimes gets frustrating after a while.
But over all this game is a great game, good campaign and good multiplayer. If your thinking about getting I suggest you get this game.