opa1632 VCOM in differential output driver configuration

Hi all, please help me understand how to connect VCOM in differential output driver configuration. I understand the VCOM function when OPA1632 is used as ADC front end, biasing... But should I leave it open, grounded or grounded through appropriate capacitor  in differential output driver configuration. I saw all of 3 option used but can't figure out the difference.

Thanks