Something is confusing me. I thought that Trenitalia and Italo used the same tracks and stations but completely different trains. When traveling from Florence to Rome a couple of years ago, we pre-booked the tickets on Italo and we were very pleased with everything. The train was very nice, not at all crowded. We'd been told that since its a private company, you've protected yourself against the risk of having your journey cancelled due to a national rail strike. When there is a national rail strike, the Trenitalia trains do not run but the Italo ones still do. Or at least that's what we were lead to believe.
So what's confusing me is that in checking schedules and prices for a date in April to go between Rome and Naples, both Trenitalia and Italo are showing a noon departure from Rome that arrives in Naples at 13:12. On both websites, it is indicated that the train is Frecciarossa #9519. On Trenitalia, it can be booked now for 24 Euro. On Italo, the price shows up in USD. It can be booked now for $29.
Are they the same train? If so, what considerations go into booking it on the Trenitalia website versus the Italo website? I think the latter is easier to use.