Hand checks:
Rth seen by C = 1.59 kOhm || 1 MOhm = 1.587 kOhm approximately.
Low-frequency loaded gain = 1 MOhm/(1 MOhm + 1.59 kOhm) = 0.9984 (-0.0138 dB).
Pole fc = 1/(2*pi*Rth*C) = about 1.003 kHz.
At fc the response is approximately 3.01 dB below the low-frequency gain and phase is about -45 degrees.
At 1 kHz transient drive, VOUT amplitude should be close to 0.707 V after settling.
