I read Artist's Way and felt that Julia was excessively dogmatic about Morning Pages. Just because doing them her way worked for her doesn't mean that tweaks won't work just as well for others. My friends call my husband and I vampires because we get up around 10am and go to bed around 2 :30am.
Trying to do this in the morning when my brain's in neutral gets nowhere and I have better things to do than write 3 pages of nonsense. Writing at night to get what's whirling in my brain on the page makes a WHOLE lot more sense. There'll be few complete sentences and much will be tasks. It's far more useful to clear my mind before bed than to peer through the "morning" fog.