For the single-ended topology, using the equations for cascaded noise figure and IP3, it is possible to calculate the input referred RF performance. For this example the input referred IIP3 is 18.8dBm and the noise figure is 11.4dB. This results in an SFDR (spurious free dynamic range) of 76dB for a 5MHz analysis bandwidth. The cascaded power gain is 14.7dB with an input referred full-scale of -10.7dBm. Using the same equations to calculate the input referred RF performance for the differential approach results in the following. The input referred IP3 is 21.5dBm with a noise figure of 13.7dB. This results in an SFDR of 76.5dB for 5MHz analysis bandwidth, 14dB of cascaded power gain, and an input referred full-scale of -10dBm. The numbers for both approaches are quite similar.  However, the active, differential, approach has higher distortion performance, with the noise figure being slightly higher. Also, the spurious free dynamic range is higher with the active configuration. Keep in mind that the input referred full-scale for the single-ended approach would be only 6dBm without the IF amplifier. It should also be noted that the differential anti-aliasing filter would require twice as many series elements as the single-ended approach. Still, the passive interface often requires more resistive padding and needs higher output power from an upstream driver, which typically means higher supply current. Also consider that single-ended driver amps tend to have worse even-order distortion and CMRR and PSRR. Therefore by eliminating the ADC driver, amplification needs are being moved upstream. The differential approach would be the logical choice based on overall performance.