In the original game, defenses were ridiculously overpowered. To a great degree this has been resolved in Forged Alliance, especially when it comes to experimental units.

The added units are nice, but there’s something even better: a fourth faction, the Seraphim. Their units are quite interesting, especially in appearance, and they’re definitely worth checking out. To do so you’ll have to play skirmish/multiplayer mode, as there’s no Seraphim missions in the campaign. The plot is actually rather interesting, the levels are more challenging than the originals, and you start at the highest tech level. It was a pretty common situation to actually never see your enemy’s base. Forged Alliance greatly improves this: units in general can see much farther, most units have radar or sonar- and all have had their ranged increased. There are also methods other than spy planes to scout enemy positions.