I had a lot of fun, but I would say that Planet Terror is definitely the best part of the movie. I could've left after the mid-point trailers and been perfectly happy. I don't think Death Proof was bad, but it didn't really stand out. Tarantino likes long talking-head scenes too much. There was a lot of time spent with characters just talking about nothing really. I wouldn't even call it character development, just jabber. There were some good scenes, and I did love the way it ended, but if it was a standalone film I would've been let down. But, as a package with Planet Terror and the trailers, just as a whole experience, it was a fun. From what I've read the 'lost reels' are out there, and will be included when the films are released separately in some countries, and hopefully they'll be included on the home video release as well. If you see it, you'll know the bits I mean. ;-)
I think it is definitely worth seeing. Lots of fun. :-)