Has owned a Tarmac SL7 from new since 2022 and rides it often. Sees no reason to move to the SL8 or SL9: the frame is still stiff and aero, with internal routing and room for 32 mm tyres, so only parts or wheels would change.
“I ride mine often and have had it new since 2022. when I ride that bike, I see no reason to upgrade. only components if I choose or wheels. frame is still plenty still, aero, internal routing, clearance for 32”