Since it is a generic question better than ninety percent of cars will not have a torque converter drain I suspect. So if a power flush change is available on a newer lower milage car it might be considered.

I have never had one done myself. Plus I seriously doubt I would have one done on an older automatic transmission.

Really though I think the partial change is well calculated with a new Filter installed by manufacturers. If the fluid looks bad enough perhaps a couple of rapid changes might be considered. If the fluid smells burnt and is really off color perhaps it either was never changed or the transmission has seen better days.

This area will probably have many different opinions by individuals. It is close enough to an oil thread type of thing.