Who has compared the Nautilus 800N/ Sig with 800D?

People react different to coments on the Nautilus 800N and Signature compared to the 800D? Why do some people prefer the old one instead of the new Serie. I only had the chance to listen tot the 802D. I liked the sound of the mid and high. But I didn't like the low freq. I heard the same hum in the low freq. as my old 802N did. This was a demo with a new Levinson power amp. I bought a pair of Nautilus 800N's of only 3 months old. But I am also interested in the new 800D.
Havnt heard the 800D but I think the 800N is the best 300 pound monitor Ive ever had.