Dual stage fuel injection, twin cam, 4 cylinders, 16 valves, 12.2:1 compression ( possibly requires high test fuel ) close ratio 6 speed transmission and 110+ horsepower in a stronger and lighter chassis, by comparison to many non ‘super sport’ motorcycles having an even larger displacement. Some of this comes from the super sport class bikes sharing technology originally designed for MotoGP racing. More power calls for more brakes and the CBR 600rr has brakes that would put many cars to shame. ( even has optional ABS ) It’s sometimes easier to identify a super sport performer at a glance, by looking at their brakes.
Similar bikes in super sport class include; Ducati 848, Kawasaki Ninja ZX-6R, Suzuki GSX-R600, Triumph Daytona 675, and Yamaha YZF-R6. All truly intended for seasoned riders with very deep pockets.
The bikes being recommended are single or twin cylinder machines, often with CV carburetors or milder tuned fuel injection and despite being sometimes larger in displacement, they are not as performance oriented, just as others have already said.