Jesus Christ, the dichotomy in quality between Mass Effect 2 and DA:O is fucking staggering. I managed to run into an awesome DA:O bug that unauthorized me from using any of the DLC I had paid for, and that took a couple of hours to fix (including redownloading all bajillion gigs of DLC). The Mass Effect 2 DLC is a ton of fun. All of it has a nice length, about 1-2 hours or so each and all involve some nice additions to the story unlike the Dragon Age DLCs which are all incredibly lazy, all of which just reuse assets from the vanilla game. Almost none of the DA:O DLC have new locations. They're over in about 20 minutes each and the God damn Darkspawn one didn't even bother to get someone to do voiceovers for it.
Mass Effect 2 DLCs: Work when you download them, are good.
Dragon Age Origins DLCs: May work when you download, are terrible.