can you get hold of a copy of Barry Thornton's book The Edge of Darkness? he devotes a substantial section to this very subject.
I do use a glass carrier, for both 35mm and MF and find it equally as important for both. I did take the glass out for a while thinking it was unecessary and my negs popped out of flatness with the heat causing uneven sharpness etc, so I replaced just the top glass and the problem was solved. Dust isnt a huge problem as it only takes a few extra puff from my bulb blower and a quick wipe with the back of my hand (a tip learned from Barry's book).
This is one of those subjects that people always seem to disagree on, so expect some contradictions ... but glass gets my vote.