So I finally got to play through Omega and Citadel DLCs.  I had a Shepard that I played through ME1 and 2, but not 3, so I decided to use her.  I thought the Omega DLC was really fun, and I liked the atmosphere a lot.  I really liked the level design, and the Adjutants were fun to fight.  The story not particularly compelling, and I was really disappointed that we were't really given a good opportunity to walk around the station after it was finished.  
The Citadel DLC, on the other hand, was absolutely fantastic.  I still haven't done the party (I'm waiting until after Horizon), but I beat the story portion and have done most of the character meet ups (except Miranda).  This is such a great way to end the trilogy.  I thought the story missions were fun, and it was great to have Wrex as a squad mate again.  I've gotten addicted to playing Armax Arsenal Arena with my ME2 squadmantes.  
After I finish this playthrough, I'm going to go back to my original Shepard's save file, and just run through the DLC.  She chose destroy, so I can head-cannon that it takes place after the end.  What a great way to say goodbye to Shepard and her allies.