Emily,

They're expensive, heavy, and require batteries.


Look again - at all of the factors you mention.

Expensive? You can get excellent ANR at a price below the passive DCs.
Heavy? Pure BS. The top-end Lightspeed is lighter than the passive DC,
not to mention the featherlight Bose.
Batteries? well, tere is one model powered of the mic power, there are
on-board powered variants, and the battery models run 20 to 50 hours on
2 AAs. Who cares?

--
Thomas Borchert (EDDH)