US mechs tend be rather cost effective, second only to the Soviet Union in terms of bargain prices. Parts and units are well stocked in supply depots, and are easy to replace.
In terms of quality, US mechs have overall mediocre stats. No huge advantages in performance over the competition. Some US mechs have a troubling tendency to catch fire rather easily.
The best feature of American mechs is their reliability. Repair kits and repair actions are more effective on US mechs than any other nation. Reliability also manifests in terms of good mobility, and less tendency towards being overburdened and broken down.
Just as repair kits are more effective with US mechs, extra gas rations are also more effective. American mechs tend towards versatility and compatibility. Enemy components are easily integrated.
US mech weapons excel mostly in the medium to lower caliber range. You will not find too many US made options for heavy mech weapons. American mech melee gear is very industrial in flavor, rather than medieval. For example: jackhammers and circular saws as opposed to warhammers and swords.