I get his reasoning, but yeah I don't think the shaving quite works. I did like the new 'Alien swinging in the chains shot'.
Interestingly, in one of Michael Palin's diary books he talks about an early screening of Alien (he was on the board at Shepparton I think), and says the movie never tops the chestburster scene. So perhaps there was some justification for speeding it up even back then?