End of Rome visit/advise please

There is a slight advantage time wise to staying next to the airport. An extra hour of sleep. Your 6.30 flight will be a connecting flight to another European city so you can check in around 5am and be OK. OA is not convenient from the airport. On the same side of town but that is about it and it is some distance. It is big park with very little around it in the way of city or eating. I would not try to do that. It is not real workable. I would stay in Rome that later afternoon and come to the airport hotel early in the evening. Little to do around the airport.

Google maps shows it around 7km from airport hotel and around a 15 minute taxi ride... how much further/longer should I expect if we wanted to go?

I think OA is a great place to visit and it is easy to do from Rome with the train. However, it is a big park that is not frequent by many tourists. There is no taxi stand. And really there is nothing else around it except mostly residential as I remember. I do remember looking down a street and thinking I saw a bar. You can get there via taxi but returning could be a bigger problem because you will have to call a taxi. I just don't think it is worth the hassle.

Ahhh- so it could be tricky finding a ride back over to the hotel since there isn't a good public transit route between the two. Gotcha.

Getting an extra hour of sleep by staying at the airport isn't, in my opinion, worth passing up your last afternoon and evening in Rome. People get taxis to the airport from Rome at that time of the morning every day so that's not a problem. Just something to think about.