We used George for sightseeing as well as transfers. He picked us up at the ship, took us on a 1/2 day tour - Acropolis, Archaeological Museum etc. Then the next day he picked us up at our hotel and then picked our shipboard friends up at their hotel and took us to Delphi. Finally he took us to the airport the following morning.

He is not a licensed guide so he cannot accompany you to the Acropolis, Museum etc. But he certainly knows alot and is happy to talk about it while driving. He also had a number of guidebooks in his car that we could refer to.

We stayed at the Grande Bretagane - this was before the recent remodeling - personally I thought it was not great, but it is supposed to be much better now. It is in a great location. I'm not familiar with the MArriott - maybe someone else will respond.

Another museum that is just great in Athens is the Benaki Museum.