Cannondale: 2013 SuperSix Evo Ultegra Di2 ($2000) or 2017 CAAD12 105 Disc ($1600)

Hi,

As stated I’m currently entertaining the following bikes. Both are basically in almost brand new condition barely ridden. I’m looking for a faster ride as well as comfort for rides 40-60km. Prices are in USD. 

Is the gap between a newer 105 (5800) versus older Ultegra Di2 (6770) less than I think it is? 

2013  SuperSix Evo ($2000 USD, $5200 USD new)

– Barely Ridden, 30 miles 

– In storage for 4 years – potential lack of maintenence issues? 

– 1st gen Ultegra Di2

– Comes with 2 water bottle cages, speedometer computer

https://images.craigslist.org/00E0E_fD3KQY3Cvbj_600x450.jpg

2017 CAAD12 105 Disc ($1600, $1850 USD new)

– Used for 5 rides as per the listing

+ Disc Brakes

+ Comes with Shimano Ultegra Pedals 

https://images.craigslist.org/01111_hFL8xrEtt6R_600x450.jpg

Which one would you guys pick and why?

Thanks!