I play mainly in 3D zoom in and out, although I have my fingers over the 1-4 keys during the replay so I can switch at will between 3D and 2D to get the overview and see exactly where the troops I'm watching move are. I use the 2D views for planning too. But I do like the immersive feeling you get with 3D, especially with some of the great graphical mods that are available. The Rolf Hall 3D icons are superb and there are lots of great terrain mods too.
[url="http://homepage.ntlworld.com/a.r.barlow/acwgc/acwgc_personal_record.htm"]General Antony Barlow[/url]
[url="http://homepage.ntlworld.com/a.r.barlow/acwgc/aoc.htm"]4/1/XX, Army of the Cumberland[/url]