Finally I got the new video screen and we tested it yesterday. 2.4 meters is the optimal screen size for my projector and our living room.
You can watch from any angle, the picture is at least 4 times bigger then our 47′ TV. There are some problems now with the quality of the movies that we watch. XviD on Projector is like screener on Laptop 
But all 720p movies are crystal clear, like you are in a movie theater and even better.
The only problem yesterday was that we ran out of beer 
