Everyone takes Piccadilly Line from Heathrow because that's what they've always done. Elizabeth Line runs a direct route through central tunnels cutting 15 minutes - 31 minutes Paddington vs 45+ minutes Piccadilly Circus.

Elizabeth Line costs £12.80 vs Piccadilly £6.70 peak contactless. More expensive but time savings plus proper luggage space justify costs. Elizabeth Line features air conditioning, wider carriages, step-free access most stations.

From Paddington connect Circle, District, Hammersmith & City, Bakerloo lines. Much easier than changing crowded Piccadilly Circus interchange. Service every 10-15 minutes vs 5 minutes Piccadilly but speed difference compensates completely.