We came to Rome from FCO with the van suggested by Giuly&Paolo. It was a 1/2 hour trip to San Pietro apartment. Paolo was waiting for us when we arrived and was very helpful.
The apartment is well equiped and very well located. It is walking distance from many wonderful spots like Vatican, San D'Angelo castle and Trestevere. The Coliseum I'd about 30 minutes walk.
We recommend it for sure