I chose the Aethos Expert after putting over 8000 miles on my gravel bike in the prior year. This was a significant move up from an alloy frame, not to mention the carbon wheels, too, and electronic shifting, hydraulic brakes. When I ride, it is a minimum of 20 miles, and often 40 to 60 miles, 5+ days a week. So, comfort was a must. My local bike shop and Specialized dealer in NYC was great -- Hilltop Bicycles. Thanks to their generosity, I test rode different Specialized and Aethos models and frame sizes. The perfect fit turned out to be the Aethos Expert. It is light, fast, subtly flexible, and very comfortable for long rides with some long, steep climbs out of the city. It is also responsive for dealing with the bumps, hazards, and unpredictable pedestrians and other riders in the city.