The 2.0 fixes the low frequency and high frequency extension problems for the Ack (at least in my system). I however have not heard the E5. I just took my 1.2d to my friend's, who has a Proceed CDP. The Proceed CDP I thought was nicer than the Ack 1.2d. We did not use the same interconnects, though, and I also accidentally reversed the interconnects I brought. I have the Proceed PMDT, which is a trasport only. In my system, the Ack Dack 2.0 is better than using the DAC in my Proceed AVP. Additionally, I've compared the Ack 1.2d versus a Shengya, and like the Ack better. However, again I used different interconnects. (I did this so that I could switch back and forth between the two.) Did you use the same interconnects?