It's a touring bike with very heavy wheels.

Weight will make the biggest difference when climbing and if you do a lot of climbing a few pounds will add to your fatigue by the end of the day.
You can go to a site like analytic cycling and plug in the numbers to see how much difference a given weight makes on a given climb.

At 205#, I am no weight weenie, but I can feel the difference between a 22 pound bike and an 18 pound bike. I can also feel it when I gain 4 or 5 pounds on the body.
On flat ground it doesn't make much difference, except during accelerations. Having climbed with a 55 pound touring bike, I can say on the flats it isn't as dramatic.