I stayed at the Central Park CY last year. The train station is a very easy walk just behind the hotel (5 minute walk max) with easy transfer to the metro line. Be careful about which train you get on coming back though as not every train will stop at Gemelli. We were treated to a nice tour of the Rome countryside as the train passed Gemelli and kept going for a good half hour before it stopped and then waited for another train to take us back. As a Platinum I was upgraded to a top floor room with a view of St. Peters. Also got free breakfast in the basement floor breakfast room. Staff was average.