I would love the CF 8.0 SL for 400€ more, with DT Swiss 1400 wheels and Ultegra groupset, but according to their size chart, I’m a S size, and they only have XS or M.
Do you think I could fit in a XS or an M at 175cm? 
Edit: I’ve been looking at the dimensions and geometry of both the Speedmax CF and the setup I have in my road bike (with the aero bars), and I actually think the XS might be the right size for me.
Decisions, decisions 