I'm playing Awakening now. I honestly don't know how some people are finishing it so fast, as I've played about 6 hours so far and haven't even gone to Amaranthine yet. That aside, one note about DLC items:
they don't carry over into Awakening, except the Return to Ostagar items. This is by design, although I'm unclear as to the exact reason behind it.
As for the game itself, I'm so far satisfied with my purchase, but if you're waffling at all due to the price, I'd suggest waiting. There are some issued with it (pick pocketing is broken in the latest patch, which Awakening requires), and there are some things that just don't sit well IMO (the usual epic scaling scenario where all those monsters you killed at lower levels now carry 2 or 3 gold instead of 2 or 3 silver or a handful of coppers, and even the grunts are using tier 7 items). But so far the story seems to be good and the companions I've recruited so far are well written.