There's already a thread on Witch Hunt.

The companions in Witch Hunt feels like the only new content. The rest is just reusing old stuff that a module-maker for NWN could put together in a day or two. It's strange to say this, but Witch Hunt made Operation Anchorage for Fallout 3 feel like premium content!

As far as I concern, Golems of Amgarrak is the only proper DLC for Dragon Age. It isn't the best DLC I have played, but it is what a DLC should be. It have it's own new story, the maps and content is exclusive for that DLC and it also have new gameplay.

Leiliana's Song is ok. It reuses some areas for sure, but it offers exactly what it promises to offer. I enjoyed it for what it was. It's like a tale told through the Dragon Age engine than a game in itself.

That said, I wonder why you ditch Awakenings. As far as I concern Awakenings did have some strong bugs (one forced me to use the toolset to fix my savegame), but it's definitely a good game in it's own. The areas are better crafted and more beautiful than Origins, the companions are very well done (two of them are among my favorites), the plot is decent, the new villain is one of the more complex you met in recent Bioware games etc.

If you enjoyed Dragon Age you definitely owe yourself to play Awakenings. Just be sure to check the boards before going into the mines (that's all I will say to save you spoilers).

A really cool area in awakenings (not the mines though);