Most operators should run a mix: keep cash as the "no-tech" fallback, capture tips at card terminals where guests already pay, and use QR tipping to cover service moments that don't naturally hit a terminal (housekeeping, dock return, valet, shuttle drop-off, room service). The right blend depends on your guest profile, where tipping actually happens, and how much operational friction you can tolerate. If you add QR, treat it as optional, transparent, and low-drama—an easy way to tip when cash and terminals miss the moment.