I don’t know if the original poster made a purchase yet, but I own a Diamondback Century 5C, the red 2017 Ultegra that lines up with the 2018 6C (other than generation of Ultegra) and I love it. I actually rode my first Century on the bike and had 1,400 miles in for the season. Not many miles compared to others here, but by far the most I have ridden in years as a 58 year old with back and neck problems. I came from a Cannondale Optimo Cross disc bike, and the ride difference is stunning. The carbon really soaks up bad PA roads, and the ability to run fat tires is great. I’m running 34’s right now. The Century flys up hills, has the gearing my older legs needs, and with the discs and stiff carbon main frame you can truly scream downhill.

With all that said, my bike arrived needing the disc brakes to be bled. I am a past mechanic so no problem, and Diamondback showered me with compensation in the form of tubes and parts etc for my trouble since I took care of it myself. They do stand behind their products, they are responsive, and as long as you are comfortable doing a little wrenching I would not hesitate to buy Diamondback. If you want shop support REI and Performance were carrying Diamondback last year.

Good luck