"Planet Terror" isn't really an homage to grindhouse. The first two thirds of the film are Rodriguez's emulation of both George Romero (think The Crazies more than Dawn or Night Of The Living Dead) and John Carpenter (Assault On Precinct 13 , Halloween, Escape From New York, The Fog, The Thing). Rodriguez does all this really well with his digital toolbox. And it's a cool cast. Great fun! Great score! Technically brilliant.
The last third isn't as strong or tight, and is really about James Cameron more than anything else (Terminator and Aliens). If you've seen El Mariachi, you'd know already that Rodriguez has a hard-on for Big Jim. By the climax, Rodriguez is again revealed to really not have alot on his mind. He won't fool me into believing he's actually interested in that female empowerment theme (ie: Rose McGowan's arc). He's just aping one of his heroes. Only homage.
The missing reel was awesome though. Not just because of the sex scene being cut, but Freddy Rodriguez finally telling Michael Biehn about that 'thing'!
Death Proof - LIKE ALL TARANTINO - is part homage and part commentary/subversion of genre (He truly is the "trash" answer to Godard). The first half is the classic serial killer genre done as the grindhouse redneck car-chase movie. Introduction of women/victims doing and talking about mundane things (of course, with the Quentin stylistic syntax)
WHAM! BAM! EXCITING MURDER SEQUENCE!
(btw, THAT'S the grindhouse mo. Mundane merging with the sensationalistic).
I think because Quentin does the murder sequences (and the portrayal of a cold blooded monster) so well, many folks would have been happy with just a 'straight' serial killing telling. With Kurt Russell's fascinating Stuntman Mike, I don't blame them.
But Quentin will always be Quentin. And the structure/vision for this flick is gonna drive some folks nutty.
I loved the second half, btw. By the last minutes of film - as Stuntman Mike gets the heightened exaggerated living shit kicked out of him - I was laughing uncontrollably

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Yeah, I left the theater with a big smile on my face.
The car/chase/murder sequences are AMAZING.