Optional Rule Guide Manual defensive fire

[typhoon]

Just got back into playing Panzer Campaigns and the ACW titles which I used to play a lot and find that manual defensive fire is hardly ever used in PBEM games. Now I only have two of the Napoleonic titles and found it tougher to like than the other two series but thinking about trying it again and prefer PBEM. I have read the optional rule guide and found that the use of manual defensive fire is recommended to give realistic results I prefer this but would like to know if most people use this option in PBEM games as it would significantly slow games down? On a side note I would also like to know if the Campaigns are played? I think I would prefer a campaign to an individual battle any feedback appreciated.