This question is about the Dune books, but it was inspired by watching the trailer for the upcoming Denis Villeneuve Dune move: in the trailer there are ornithopters (actually technically entomopters in this version), but there are also giant spacecraft that can hang in the air with no visible means of support.
Now I remember from the book that in the Dune universe there are suspensor fields, which are used to hold up such things as light fittings, hunter-seekers and the Baron's rolls of fat, so it makes sense that a suspensor field could hold up a spacecraft or large aircraft as well, but it makes me wonder the following:
Is what's shown in the trailer consistent with what's in the book, that is, are spacecraft, carryalls and so on powered by suspensor fields or similar technology? (Or are the carryalls actually supposed to be giant ornithopters?)
If the answer to (1) is yes, is it explained in the book why ornithopters are used for carrying people, rather than comparable craft that use suspensor fields instead? e.g. is it because of speed and manoeuvrability, or to prevent worms from being attracted? Are they used only on Arrakis or are they common everywhere?