Paul's visions in DUNE.

[BrianSoddingBoru4]

Possibly the only group that could afford really massive Holtzman generators was the Spacing Guild (they used the field to warp space). Which may also explain their exorbitant shipping fees.

Boru

The Atreides sea carriers and vehicles smaller used suspension.

Well, Herbert isn't answering his cielagos so we'll just have to deal with it.

Another thought: the novels explicitly mention that shields can’t be used in the desert, as they attract sand worms. Since the same energy field (Holtzman effect) that powers shields also makes suspensors work, equipping spice-mining equipment with suspensors would make spice harvesting impossible.

Boru