Xur is once again here and despite landing exactly on the Christmas Day, he didn't bring any special presents besides the regular Exotic loot pool to sell to Guardians who amassed Legendary Shards.
Bungie has a reputation for being stingy and the latest reasons for being branded that way are the Bright Dust changes along with sunsetting that almost everyone hates. They might some more flak after not offering anything special with Xur, despite the "Destiny Santa" appearing on December 25.
Anyway, you can find him in the Tower's hangar. If you are unsure how to get there, put a waypoint on Amanda Holliday, fast travel to the Courtyard and proceed to meet her. When that happens, turn left and go toward the pad where the aircraft is landing but keep an eye on the catwalks to your left, which is where you will see Xur, as depicted below.
He is offering D.A.R.C.I. this week. The sniper rifle is useful for picking up data on specific combatants or measuring range at which you engage but other than that, you always have better alternatives, no matter the situation.
Hunters are getting the Sixth Coyote, which will give them a second dodge charge. While this can be useful in certain situations, it will always be beaten by the Mask of Bakris which is a superior boost to the class ability.
Titans can purchase the Ashen Wake gauntlets. These are useful in the Crucible playlists that feature 6v6 fights since they will allow you to stack up ability damage with the middle Solar tree, which will eventually let you one-shot Guardians with Fusion grenades which will explode on impact and recharge instantly.
Karnstein Armlets can be useful for Warlocks gearing up for close-quarters combat in PvP as the Exotic will refill their health upon melee kills. It doesn't need to be a powered melee kill, which can make these gauntlets absolutely brutal at times.