Riders who race or ride fast on rolling and flat roads and are happy with a long, low fit. Not the pick if you want a tall stack.
A deep-section race bike that wants speed. The cockpit is integrated and the front end is stiff; it holds a line in crosswinds better than older Aeroads, but it still feels like an aero bike.
Riders who want one Trek race bike now that Émonda is gone. If you liked a low Madone or a light Émonda, this is where both fits land.
Gen 8 Madone folds the Émonda brief into the aero bike: Full System Foil shapes, revised IsoFlow, and a frame roughly 320 g lighter than Gen 7 while holding the older Madone's speed.
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.
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.