Although the Atrium is a little outside of the city of Athens Proper, it is close to the bus lines and is only a 15-minute cab ride to "downtown". The hotel itself is lovely, clean and secure. The rooms were spacious and had all the amenities you would need. Our room was a king, and we had only a shower, no tub. This isn't an issue for us, but if you like to take a bath, be sure to ask for a room with a tub. The wonderful soaps and shampoos (all olive-oil based, of course) were delightful.
The staff is INCREDIBLE...they made the stay extra-pleasant. Dimitrius at the front desk was phenomenal, helping us with cabs, reservations, ideas for things to do and see, etc. He is tremendously knowledgeable about the area, and speaks great English. He was a true delight.
Additionally, Jannis, the bartender/waiter/man-of-all-information was a true treat. He, too, helped us with information about the area. He even spent some time writing our names in Greek letters (we were a group of 12) and helping us with our greek pronunciation. He was just a great guy!
The food at the hotel is great! The breakfast buffet is large and varied. The bar is well-stocked with known goodies, as well as a variety of Greek beers and ouzo. The dinner menu at the hotel is varied and delicious.
I would definitely stay here again. It is truly a lovely place.