Disregarding the technical flaws (of which there are many, I'll concede that) I think DA2 was a very good thing to happen to the medium. Especially BioWare's catalogue.
In direct contrast with Mass Effect 2 which, in as good as everything but its technical achievements (save the characters, which is the one thing you can trust BioWare with getting right most of the time), was a complacent and uninspired affair, Dragon Age 2 took risks and dabbled with the formula, delivering a diametrically different experience from what could've been a really cheap cash-in.
Origins 2.
Personally, that would've felt like a short-handed approach.
Furthermore, it's probably the most socio-politically charged game I've played since Far Cry 2.
Origins, regardless of how finely written it was, never really went further in its thematic contents than the proverbial "beat evil over the head with a big stick". Like I said, an interesting and finely crafted big stick, but a big stick all the same. The most challenging narrative devices and ideas were found outside of the main storyline, and more often than not ended up reducing what dilemma there was to a simple binary choice.
Dragon Age 2 is heavy-handed at times, certainly. But there is a specific decision in the midst of act 3 which caused my mind to enter the morally relative equivalent of "Enter the Dragon".
That moment alone would cause me to dub Dragon Age 2 BioWare's greatest achievement in storytelling yet.
Good thing is, there is a plethora of multi-faceted characaters to boot. Isabela, for example, is easily the best written romance ever portrayed in a BioWare game.