I preferred Origins overall, but I can't say it was perfect. I thought the combat got repetitive, I thought the storylines needed to get much tighter and more cohesive (too many threads going nowhere), I thought the combat was less tactical and more statistical (as in, it's more about the numbers and buffs rather than positioning or strategy) and overall, I didn't like the feeling like I wasn't really in control. I described it to my friend as "a single-player MMO."
But Dragon Age 2 took everything I disliked about the first game and made them bigger. More enemies - and after you kill enemies, new enemies respawn immediately. Enemies rush you en masse and swarm you - the only tactics are what buffs and special attacks you use and the stats of your characters (also, the enemy AI was really unintelligent - they just attack you in melee and use their specials - just all, so basic). And the story was really, really drawn out. Spoilers:The whole first part builds up to this big treasure hunt ... and storywise, the only thing that's significant is that they find a lyrium artifact that's never mentioned until momentarily at the very end. Okay, it makes Hawke rich ... but did we really need to devote a third of the game to "Hawke invests in moneymaking opportunity, investment pays off"? And the second part - this whole big thing about the conflict with the Qunari and oh sh** some major story points coming down ... but then the rebellion happens in a blink of an eye and the Qunari go away and what was the point of that again? Oh, sure, we now know Hawke has become a respected hero in Kirkwall as a result - but did we need to devote a third of the game to it?
The only really significant plotline comes at the end - the Mages and the Templars. Threads of it are weaved throughout the first two parts, and it's clear from the beginning that that's the true focus of the game's main storyline, but nothing develops until the final third - and that part, ironically, feels kind of rushed.
I would have much preferred a complex storyline showing the detailed build-up to the Mage-Templar conflict, the individual figures in the story, their relationships and rivalries to each other, instead of all that stuff about "Hawke becomes rich and then a hero" that the first two parts are devoted to. And we do get some of that ... but the whole game should've been devoted to it.
My strong suspicion is that Dragon Age 2 was actually supposed to be released episodically - "The Adventures of Hawke," more or less. The first part was supposed to be "Hawke, Rags to Riches", the second was "Hawke Becomes Champion", and the third: "Sh** Gets Real." These three episodes were supposed to be a sort of companion/sequel to the original Dragon Age, bridging the gap and setting the stage for the true sequel, which is what we're getting now. I imagine that the whole framing device of "Varric Tells Stories About the Champion" was originally intended for that episodic release.
So, in the end, Dragon Age Origins felt more complete to me, while DA2 felt like it was rushed - like a project got condensed and then released without all the trimmings. Or, alternatively, like the project was supposed to be released immediately after DAO, got delayed, and then just released all at once. I sense a lack of gameplay refinement, and the repetitive environments and respawning enemies (as well as smaller environments than the original, where large environments allowed for some semblance of tactical gameplay) were shortcuts to tie up loose ends.