Compared to Virhin Australia crew, Delta staff seem almost poorly trained in comparison. For example, Drlta crew don’t check your pass, don’t immediately move down the aisle to move along tourists busy discussing their seats and then line up for Boarding seems chaotic at best.
Take a long time to taxi to the gate & getting off the plane.
Boarding was swift and cabin crew where attentive. Baggage drop was swift and luggage arrived quickly. Global entry at ATL was swift.
delta security in the UK is an absolute farce. The security screening at LHR was long and understaffed