Racers and fit riders who want Giant's race geometry without Propel's deep tubes.
Giant's lightweight race bike: compact sloping top tube, sharp steering, and a fit that has been a stack/reach reference for a long time. Less aero drama than Propel.
Racers who want BMC's classic race fit. Roadmachine if you need stack.
BMC's lightweight race bike: steep, precise, and a WorldTour stack/reach reference. Less aero than Teammachine R / Timemachine.
Racers who want a climbing Orbea. Orca Aero is the wind-cheating sibling.
Orbea's lightweight race bike, OMX carbon on high kits, and a fit that is race-low without S5 drama. OMX vs OMR changes weight more than geometry.