I have to say the Ninja 300 build and finish quality is impressive. Honda is using heavier, cheaper (more reliable?)components.
The CBR500 has larger ergonomics. They are going for the crowd that commutes and is looking for a reliable sporty ride without feeling like they are too big for the bike. That torque in the lower revs makes all the difference.
HP is a fake number that means nothing, and is just used for marketing, the torque charts tell a very different story, you really have to wring that 300 to get that power. Yeah, 430lbs is lardy, but likely better on the highway.