Why not read up on the equipment page, click on “More Product Details”. There is lots of good info on those pages. After reading you will be able to understand the differences, seeing as you own a NuWave DAC, and know what it is capable of.
I think there are two important differences, the new DAC is also a full functioning remote controlled preamp, and with the DMP transport you will be able to send SACD’s DSD to the new DAC when using the I2S input.
As far as sound quality differences, I have yet to see a comparison. If there are any, I have missed them.