Good tactics. The flame tank rush is definately the most successful tactic for Nod. I have actually been on a team that defended against the 6 tank flame rush. All it took was 3 good medium tank drivers. Each medium tank should be able to take out one flame tank before they get to the AGT. That leaves three flame tanks and the mediums should still have good health. You simply block the entrances while shooting at the tanks that aren't right next to you. That was first (and only) experience I had at successfully defending against 6 flame tanks on that level. 3 or 4 isn't so bad as long as someone is repairing the AGT.
One other thing that helped one time for defending the AGT against a flame rush.. when we saw the flame tanks coming, all the people not in tanks put timed C4 all around the AGT. It actually worked pretty well, but it might have been dumb luck. Usually, the best luck I've had for GDI is to keep Nod on the defensive so that their flame tanks don't get a chance to group up. Just don't leave the base completely undefended.
The only problem with the APC rush is that you MUST have disposable people in the APC. The obelisk is usually loaded with mines and the first couple of people to go in it will die.
Anyway.. those are just a couple of my game experiences.
[ April 22, 2002: Message edited by: kubi0461 ]