I was in your same situation (but lower budget) when I went bike shopping. I ended up with the Canyon Endurace. I am very happy with that decision. It replaced a 2008 Specialized Tarmac. It's every bit as fast (at least as fast as the rider can ride it) and it comfortable enough for multi hour rides. Plus you get a lot more for your money with Canyon. To get a similarly equipped Specialized, Cannondale, or Trek (the three brands available locally) I was going to pay $1000-1400 more. I went with 105 because honestly I don't have a need for anything higher tier. Although when they come out with the Di2 105 I'm going to strongly consider that for my next bike. I did upgrade the wheels as the stock DT Swiss 1850 kept breaking spokes on me. But I'm on the heavier side so that is probably a lot of the reason.