yeah they've been super useful for me too. i haven't switched to the multirange datatype yet (still use int4range[]), but I'm excited to since you can now do exclusion constraints on multiranges, which will greatly simplify some things for me.

i keep track of roads that a person has biked/walked for Wandrer (wandrer.earth), and storing everything as a geometry would be a storage and analytical nightmare. keeping things as a range lets you easily determine what part of an activity covered new ground, and you can generate the geometry / length on demand while only storing a few integers (plus the raw road geometry, but that's shared among everyone).