The current map pool is so varied that is almost impossible to balance out all the different factories.
The fact that some say it is OP and others UP probably means it is OK.
Me personally, i think they are a solid all round factory.
Bandits are the bomb while the roaches still steal the show (see what i did there ^^)
Their cons are the best, they have actual combat value with their shields!
These first three might just be ZK's strongest units.
The felon ball is as potent as ever.
It's AA is cheap, spammable and has epic range.
The assault Thug gives you (almost) free repairs at a dirt-cheap cost price.
Trollbags are still an easy/cheap way to scout. And can still ruin the map for all the other players (remove it from ZK imho, wouldn't make a difference to the factories potential)
Outlaw is not as OP as it used to be. I think the unit might be on the weak side, but given the list above i don't really mind.