I got it just this week. The packaging is particularly cool, I think. However, as I said previously in the "All Things Buffy" thread, as far as I can tell there's no difference in the the discs for the first two seasons in the old individual season sets vs. the same two seasons in the new seven-season set. (I only had the first two seasons on DVD before now, so that's all I can truthfully comment on.) There is a separate DVD with "never before seen" stuff, and I personally like the booklet in the new set better than the little booklets that came in my individual season sets.
I supppose it depends on how big a fan you are, or how much of a complete-ist you are as a collector, or whatever, but if I already had all seven of the individual sets, I personally wouldn't buy this.
EDIT:
For your further information, the special DVD I mentioned above says this:
5 All-New Featurettes:
"Breaking Barriers: It's Not A Chick-Fight Thing" - The Evolution Of Buffy's Fighting Style
"Love Bites" - Relationships in the Buffyverse
"Evil Fiends" - Meet your favorite Buffy demons
"Buffy: An Unlikely Roll Model" - Why we wanna be Buffy
"Favorite Episodes" - The chosen ones from cast and crew