I definately don't agree with that for some levels. Compared to the obelisk, the AGT isn't usually as fast to destroy something. 5 or 6 flame tanks will take out an AGT a lot easier than 6 medium tanks will take out an obelisk. I still feel that GDI doesn't have enough to offset the stealth ability of NOD, particularly in defenseless levels. The flame tanks are weaker than a medium tank (unless you let them get right on top of your before you fight back), but they do more than damage a single target. The flames do area damage and vaporize infantry and also severely reduce visibility. For many people, they also cause some lag increase.

I don't mean to complain too much since I've done well playing GDI, but I think that the AFT is more important to GDI than the obelisk is to NOD. At least NOD can always see incoming raids whereas GDI is dependent on the AGT to detect stealth units.

I think it'd be best if they added the ability to build a few turrets or some form of defenses, to both sides.