The InsideFlyer comparison is a bit weak because it excludes the hotel affinity credit cards, which if you use them can have a big impact on award earning (especially for Starwood and Marriott's Premier card for US residents). Starwood's Amex will give another 2 points per dollar charged at Starwood properties, while Marriott's Premier card gives another 5 points and 15 nights elite credit. That would push the 38 night guest to gold at Marriott, and it would allow the guest to earn free weekend nights using EEOs, which do not require any points.