Looking fot personal experiences. We have friends flying into Rome who need to get diwb to Naples easily. Think a bus mighth be easier for them than trying to negotiate the Roma Termini station. Thhey are not experienced independent travelers.
No personal experience -- I often share the link because I think it's convenient to get right on a bus and nap versus having the train stopover. But, there is a new train route from FCO direct to NAP, so you may want to check that on the Trenitalia website as well. It may be limited but could work out for them if they prefer train.