nht bookshelf differences- sb0, classic, superzero

Are these just similar updated versions? Superzeros, sb0/1/2, classic 0-3?
I owned both the SuperOnes and the SB-3s. They were worlds apart. The SB series build quality and sound were far superior. From what I've read, the new Classic series seems to have jumped to another level.
I disagree with Timshu...I've owned SuperOnes, SuperZeros, 1.3a's, 2.9's, 3,3's etc and recently, the SB3's, which I thought were not built as well or sounded as good as the older models...my opinion only!