Yamaha 479 will be suitable for music+ movies.
Demon x1200 if movies only. The musical performance may not be convincing in x1200. x1200 is more feature rich with 7.2 and Atmos enabled and DTS-X upgrade. RX-v479 is not Atmos and 5.1. You will find wider Yamaha service support than denon. Both the models are good and many FMs are using them. So weigh all the factors and decide. Demo is also important to zero in.
Suggest op to wait for new series of yamaha which will have atmos/dts-x. August end should be the tentative arrival of the same.