How to design BJT active filters
a bipolar running at 10mA will have Rout (Zout!) of 2.6 ohms; and you can run this circuit on 1v or 1.5 volts, unlike an opamp. Thus the bipolar STOPBAND will be far
superior to the opamp.

Note for each of your schematics, the C2 becomes a shunting path for high frequencies,
and the only filtering remains the C1 (thus one-pole passive becomes the behavior).

The 0.6 volt offset can be reduced, with a NPN/PNP Darlington.

The inherent noise of a bipolar is set by the rbb', which is the non-useful resistance
of the bulk silicon material between base-contact node and base-collector region; you should easily have this less than 1,000 ohms, or 4 nanoVolt/rtHz noise density. In 1MHz bandwidth, you'll have 4 microVolts RMS (scaled up by pi/2 or so, for rolloff) of total integrated random (and white) noise.

Thus with 1 volt PP input, and 4 microVolts RMS noise, you can expect about 100dB SNR.

Do be aware of Finite Power Supply Rejection, likely set by the Early Voltage.