1. They don't upgrade attack or defence.
2. They Don't upgrade special ability, like move faster or cloak
3. They Don't cast any ability.
4. They still can't spend their resources effectively, they don't know remote mining.
5. They move their workers around the map.
6. They go back and forth when encounter player, eventually waste so many units while falling back and suddenly go for attack. (Very serious problem, they waste units on going for attack and fall back then go attack and then fall back.)
7. They only have like one army, when they die, they don't rebuild enough and effectively even though they have so many resources.
8. They don't harass player or do a inlitial attack early in the game.