I had to laugh at the first commercials for Grindhouse
(link points to Rotten Tomatoes review page). They all said “This Film is Not Yet Rated.” Well, hey, you didn’t have to be Jack Valenti to guess what the rating was going to be, assuming that nobody involved was going to let this one into theaters with an NC-17 rating.
Although you can never tell, at the moment GH sports a healthy 87% tomato rating, so maybe it will justify depriving your butt of blood flow for the 3:10 it will take to spool out. It sounds like a consensus to me. One repeating theme in the reviews is that, unfortunately, one of the stories just isn’t as good as the other one. But there’s little agreement over which half is which. It’s anybody’s best guess that they’ll both be good in different ways.