DO
Not really, LED fixtures are similar in size to their predecessors, because you either need the optics (hard edged sources) or the size (soft edged sources). There are heat and weight benefits with using LED which means the supporting infrastructure (rigging / air con) doesn't neccessarily need to be as large as a "conventionally" lit space.
[off topic]Halogen is old-skool as far as professional lighting is concerned, having been in use for many decades.
Is it now possible to reduce the height taken up by a lighting grid if only LED or halogen lamps are used?
Not really, LED fixtures are similar in size to their predecessors, because you either need the optics (hard edged sources) or the size (soft edged sources). There are heat and weight benefits with using LED which means the supporting infrastructure (rigging / air con) doesn't neccessarily need to be as large as a "conventionally" lit space.
[off topic]Halogen is old-skool as far as professional lighting is concerned, having been in use for many decades.

