catonec 

road bikes are specifically designed to be used on the road:

your "stance" on a road bike will be more aerodynamic than a mtb or hybrid.
a road bikes gearing is larger than mtb's and some hybrids (this explains why fat roadies fly by you with less effort)
skinnier tires=higher pressure = less rolling resistance ???? idk they just seem faster
any kind of shock absorbing systems on a bicycle will "activate" under heavy torque, yes I believe it is sapping power. plus adding unnecessary weight.

so, bottom line. Should you buy a road bike? absolutely.

Will you see a significant difference over an 11 mile trip? timewise, not really a few minutes maybe. but your saddle time will be spent more efficiently and you may even arrive at your destination with a little more energy left in the tank.

One final thought. many people are "intimidated" by drop bars and the general bent over positioning on road bikes. they assume that having lower back pain will be amplified by this and opt for a more upright bike. I was surprised to find that on my roadie I have more weight forward on my wrists and shoulders, meaning less on my tailbone, which translates to a less jarring ride. sitting upright puts the force straight up and down on my tailbone. leaning forward reduces that.