Any digitization system must be preceded by an anti-aliasing filter. For wideband high frequency applications, parallel multi-rate conversion systems such as time-interleaved or hybrid filter bank analog-to-digital converters (resp. TIADC or HFB) are attractive solutions. This paper compares the robustness of both techniques with respect to non-idealities of the anti-aliasing filter (AAF). Theoretical results show that the signal-to-noise ratio (SNR) degradation due to out-of-band signals is lesser for HFBs than for TI-ADCs, provided that the analysis filters of the HFB are selective enough. Simulation results show that this is the case even for low-order analysis filters in the case of a four-channel HFB.