Hi, I will buy the NAD in a few days , i hope, i know both producers i use to work in a hi-end shop, and NAD is always the best pick value for the money, i like the sound of nad , yamaha sounds good also but they are makeing compromises at small series, i will give you a litle example: NAD C715, THD = 0,09%, YAMAHA THD= 10% wich means the YAMAHA will be imposible to listen
The specifications from above (thd) are taken from your link`s, any kind of audio product with THD (total harmonic distorsion) > than 0,1% it`s a joke and the spekers are also wery important in this ecuation.
I will strongly recomand the NAD C715 or a little more expensive NAD L54
But, its beautiful what you like, always !!
Have a nice day