The AR3 is a gravel / all-rounder bike. The Etape is a racing bike.
For bombing around at warp speed on paved roads, yeah, the Etape will be a lot more fun. It was designed to be.
The minute you leave pavement, the AR3 is the champ. Designed to tackle rough terrain and keep you on the bike at the same time.
The AR3 will never have the get-up-and-go of the Etape, and the Etape will be limited to paved roads for the most part, whereas the AR3 is multi-surface capable.
If the Etape is a revelation for you, then welcome to the club! We tend to like old road bikes here, so plenty to dive into if that's your thing.