Im not sure about the BMC Impec as its supposed to be their highest end model but the BMC RM01 is one of the stiffest dedicated road racing frames they make. Their new GranFondo is supposed to be super stiff as well but is aimed more at the spring classics. I think the BMC RM01 would be paired up against a Super Six and the BMC SLR01 Team Machine against the EVO. RM01 = very stiff, less compliant, slightly heavier. SLR01 = very stiff but not as RM01, more compliant/comfortable, lighter.