I have a Roubaix SL4 Expert and it's a nice endurance bike for the money. The CG-R seat post is a must IMO so make sure the 25mm of setback works for your bike fit. You might want to also consider the Trek Emonda since it's more responsive than the Domane. Top tube length would not be a reason to pick one bike over the other. Reach can be adjusted with a stem and/or different reach bars.