Is it possible that a new bike might make a person *faster* if it leaves you feeling less fatigued? "Endurance" bikes, like the Trek Domane and Specialized Roubaix, are relatively new to the cycling world and the technology they use to provide the improved comfort wasn't even possible until the use of carbon frames. Obviously, an 'endurance' bike won't make you jump from 17 mph to 20 mph in an instant, but perhaps it'll help you average a higher speed for longer?

Regardless, having the OP dump his current bike for an endurance bike prol'ly won't get him from B+ to A.