It had an almost unique look and feel. It just did something for me the main series and the new one just didn't. The characters were at their truest. The writing was actually pretty good - not so much in terms of the quality, but just how natural and real everything they said felt.
Random, I know. I just bought the entire '78 series on iTunes and am going beginning to end.
I liked the mini series too, BlackRose, but I thought the show was even better in the first full season. By the end of that season, I was completely hooked!