I am 61 years old and have been riding group rides for the last 15 years (mostly "A" rides on rolling terrain plus/minus 18mph, 50 - 62 miles/ride).. The last year or 2 it has been a struggle hanging in there and I have been riding more and more with a slower group. My 12 year old Specialized Roubaix needs replacing and after testing many bikes, I have narrowed it down to a 2018 Roubaix Comp and a 2017 Giant Advanced SL 2. Both bikes are so much better than what I am used to, and I am tempted to go for the Giant, but a nervous about the racing geometry. Any thoughts?