No, the 7.5% figure comes from the 5X categories (INK Cash, Freedom) redeemed through the Chase Expedia portal at the Reserve nominal value 0.015/point. 5 X .015 = $0.075. If you substitute Sapphire Preferred or INK Preferred for Reserve it changes to 5 x 0.0125 = $0.0625. How much weight you would put on this depends on the amount of 5X spending you make -and- your willingness to redeem through the portal. If you transfer to airline or hotel programs there is no unique rewards advantage to Reserve.
The break even redemption via Chase portal between having the CSR vs CSP to justify the effective annual fee ($250 vs $95 respectively) and the difference between the redemption multiplier (0.015 and 0.0125 respectively) is 62,000 UR redeemed. So, if one redeem via portal at least 62K UR, then CSR would be better than CSP.