They have a unique feature of 'connecting' with DX droids and adding the lesser machines to the control center's fighting strength, allowing the single CC to command entire squads of droids. Since DX class droids malfunction and tend to forget their target if it leaves their sight without assistance from an control center, XD droids were mobile control centers capable of processing what it's fireteam or army should do on it's own, and thus it could synchronize the attacks of it's army or fireteam to a perfect degree. Physical differences include the XD wearing a large processor pack that contains the more powerful processor, and also sport unique painting and designs. Manufactured for the highest bidder only, the XD droid is much more advanced then its older counterpart, the DX droid.
The XD-class droid is a very expensive, combat ready and incredibly intelligent droid manufactured exclusively on New Port Cache. 'XD droids?! That money is as good as yours.' - Fox buying the Great Fox III from a very wealthy gangster on New Port Cache. I offer you my security team on top of all of this, complete with Destroyer, Super Battle, DX and even XD droids.' I want it, but I could buy a battle group of cruisers with the money you are asking for.'
