One of the builds gunner plus engine upgrade has been esentially replaced with the IG-88B+C or also known as the Buzz Droids as they can take HLC and autothrusters. Slightly better firepower, much better maneuverability, only 2 hit points less but has 2 agility more also with autothrusters makes it tough at range 3.
Buzz droids have displaced the Buzzsaw shuttle.
As for doom shuttle you get more Vader when you put him on a Patrol Leader.
So yeah both competitive flavors of shuttle have been displaced by modern builds.
Edited by Marinealver