I made a few example noise and click like waveforms and analyzed with Audacity and two other systems, PULSE by B&K and Artemis by Head Acoustics.
Performance at low input levels will be determined by the hardware, not the filter implementation. The difference between your filter and the one I use (which is a reversed engineered A-filter posted by Edgar on the Audacity Nyquist e-mail list) and the link in your post is the use a bilinear transform. Edgars solution instead uses the filter design tools of nyquist (lp and hp) to create a chain of multiple filters.