Heh... I have avoided air like the Plague for some reason... I love Armor and Inf.. but it depends on the map (as in most games)... Use Special forces air drops to go behind enemy lines as spys.. Just make sure you tell them to hold fire... sit in the trees and save up points for the big damage strikes... Good stuff...
..now where did I put my keys?
Learn the shortcut keys. For example: X changes your unit formation between line and box formation, and space takes you to your drop zone. Don't use heavy artillery, you will probably get yelled at by teammates. As infantry, use as much cover as possible, trees, buildings, and some roadblocks that are on city maps. Also, at the start of the round, it can help if you wait those extra 15-20 seconds for more reinforcement points to come so you can get that extra unit (4th heavy chopper/heavy tank). It really does make a huge difference.
I am thinking about picking this up this week. I played during beta but that was like last summer and kept wishing could play with TG folks instead of some of the .. umm .. errr .. not so tactful beta testers