They've been consistently better than normal LEO. Even with the Kent State Massacre, normal cops killed more protesters around that time, and were generally much more brutal. During the George Floyd protests, local and Federal Law Enforcement did some horrible shit, but the misconduct the NG did was mostly limited to unjustified intimidation.

I think the biggest thing is that they don't instigate riots the way police do. A lot of 2020 riots, and recent riots, have been police riots plain and simple. NG are scary, but they have much more reasonable ROE, and stick to them. They aren't used to riots, so they aren't comfortable starting them.

Federal law enforcement has proved themselves the worst of what was deployed during the George Floyd protests, and there is already tons of them in Minneapolis.

The "hit or miss" is just a matter of who co tells them. Dem governors don't want escalation, it looks bad and isn't popular with their base. Republican governors, or federalized NG are much more brutal. I'd be willing to take their cookies as long as it's Walz, he won't be poisoning them.