I often wonder why the races in the Delta Quadrant seemed so pedestrian compared to those encountered in the Alpha Quadrant.
Come to think of it, that makes sense when it comes to the Borg... for 900 years, they'd been feasting on all these lame civilizations that hadn't even invented the replicator yet. That makes them a technological power, yet tactically weak. It was easy for them to take over new races because those races could barely offer up any resistance. It was futile.
Suddenly, they become aware of the Federation and their human ingenuity, and are like "finally, someone in this damn galaxy worth their salt!"