I have tried to use the new V17 built-in Slow Motion feature - but the result is not good.
Input is some 1920x1080 25 Fps 50 Mbps with shutter speed 1/250 - and it is slowed down to 0.20 using the new V17 FX with analyze= FINE:
https://drive.google.com/file/d/133h1bet6XAD4nGK0xOVedKEYtU7AQ3D9/view?usp=sharing
Look i.e. at the mans head jerking forward and backward.
Is this result what it to be expected from the new Slo Mo?