We stayed at Oaza for 10 days and even on our last day the waiter gave us a czech menu instead of an english or german written one. The personnel spoke little english and/or german and the receptionist was friendly but the waiters certainly were not. It was not possible to rent a bike, they only had three bikes for rent and they were never available. The food is fine, the pizza's are big and tasty and the prices are, as everywhere in the Czech Republic, very affordable. The room is ok, beds very hard but fine, cleaning is less, the first 3 days there was no cleaning, only after mentioning it at the reception desk our room was cleaned (reasonably). The swimming pool is small and there were school children all day on the complex. Also on the terrace lots of children having their lunch in the afternoon. They give tennis lessons at the complex to the schoolchildren and their is an international school that uses the complex too. The swimming pool is used by those children too and not much room left for the guests. Ricany itself is a small village, their is a train station with a direct train to Prague centre (approx 30 min)
Behind the complex their is a possibility to have a nice walk in the woods or a ride on your bicycle. By car you can drive direction Prague (20-25 minutes and park your car in the parkinglot at Chodov P+R, a big shopping mall with a metro station. There is also a P+R at Opatov but when you are coming back late this is not a fine place to have to walk around.
Prague is great and you should not miss seeing it by night.