Having mentioned some of this movie's flaws, I also feel obligated to point out something that isn't a flaw, but which others have called such: The dialogue scenes. Someone calling himself IndustryKiller! on Aint It Cool News put it most succinctly:
Also their conversations go on absolutely forever, especially that diner sequence, which brings the film to screeching halt when tarantino [sic] take 15 minutes to say what could easily take three to five.
I swear, all I could think as I read this was, "Goddamn, have you ever even seen a Corman-esque '70s action-horror movie at all? They were chock full of long, boring, pointless dialogue scenes. In fact, as I was putting the DVD in and started up the movie, I remember wondering how Tarantino was going to deal with/recreate the long stretches of downright boredom that tended to creep into the movies he was homage-ing. Thankfully, he dealt with it by putting in long stretches of Tarantino Dialogue™, which at least tends to be more interesting to watch than what actually ended up in most of the real '70s grindhouse movies.
I've seen several reviews complaining that '70s exploitation movies were short, and thus didn't have a lot of unnecessary stuff in them, but it's just not true. Movies today are edited much tighter and quicker than they used to be. George Lucas comments on this in one of the Star Wars DVD commentaries - that he tried to make the original as fast-paced as he could, but that by today's editing practices, it's downright flabby. That also tended to be true of the kind of movies Tarantino is referencing, and often doubly so.