Currently have a Giant Contend AR 2 w/ 10-speed Tiagra. I use it for pretty much everything: commuting\~20 miles each way, a few times a week; group rides; fitness; getting around and shopping; etc. As a result, it’s something of a “compromise bike” (dual sided flats/SPD, tires geared more for puncture resistance, fairly relaxed geometry).
Ready to get a second bike to relax the compromises, and going one of two ways: (1) upgrade current bike with full 105, nicer tires, carbon wheels, more aggressive geometry, and get a used bike with a rack for getting around, or (2) get a racier bike, permanently install my rack on this one.
In terms of upgrading, I was between the [Cannondale SuperSix EVO 3](https://www.contebikes.com/product/cannondale-supersix-evo-3-434487-1.htm), the [BMC Teammachine SLR 5](https://www.contebikes.com/product/bmc-teammachine-slr-five-32604.htm), and the [BMC Roadmachine Five](https://www.contebikes.com/product/bmc-roadmachine-five-419290-1.htm). They all have 105 Di2, and the only planned eventual upgrade would be a new wheel set.
Which approach would you choose, and if you recommend upgrading, to which bike?
by diamondium