Sprinters and fast road riders who picked aero over weight. If you wanted the climbing bike in this era, compare stack/reach against the Émonda instead.
Gen 7 Madone: a pure aero race bike built on Kammtail Virtual Foil tubes with the IsoFlow cutout for rear compliance. It is the fast, heavier half of Trek's race line — Émonda is still the light bike in these years.
CX and gravel racers who size like a road-race bike. If you want Future Shock and mounts, Diverge is the sibling.
The light gravel/CX race bike: lower and snappier than Diverge, with less adventure hardware. It feels like a Tarmac that grew tire clearance.
All-day road riders, gran fondo people, and anyone who found Madone/Émonda too low.
IsoSpeed endurance geometry: taller stack, longer wheelbase, and a rear end that takes the sting out of cobbles and chipseal. Still a road bike, not a Checkpoint.