Basically, Bioware nails it.
The most surprising feature for me was that DA in fact does not use the Dungeons & Dragons rules underneath. Instead Bioware made a new system, where characters have a pool of mana or stamina that regenerates in real time, while buffs take their toll by lowering maximum mana/stamina and reduce regeneration rates. Mana/stamina regenerates slow during combat, and quickly once combat is ended. I rather liked this, because it means you won't be holding anything back during fights because your are afraid you may need your spells later on.
Also you don't need to 'rest' all the time to regain spells. Only three base classes (warrior, rogue, mage) and three races (human, dwarf, elf) are available, but each class has four possible specializations, 'prestige classes' if you will. Spells and abilities are gained only at level-up so you will probably be second-guessing your choices a lot. Crafting materials
especially for single use items like potions, poisons and healing kits, as well as their recipes seem rare and expensive, I didn't rely on them and I don't think you can. All in all though, it's an impressive new system with both D&D and action RPG aspects.
DA does an excellent job of presenting the world of Ferelden to you. With Eye of the Beholder, Baldur's Gate, Planescape Torment, Neverwinter Nights, and Icewind Dale (did I miss any?) all situated in the world of Ferun, it is actually good to have something new. A lot of 'lore' is stored for your convenience in the 'Codex' as you discover the world. However, I couldn't bring myself to read it all in a game that took me 75 hours (!!) to complete.
There is a ton of spoken dialogue and the voice acting, facial animations etc. are all excellently done. There is just so much of it that sometimes you wish it was a little less verbose. DA is very similar to Neverwinter Nights 2, without the bugs that is. To me it doesn't quite have the strength of storytelling and characters that Obsidian displayed with Knights of the Old Republic 2 and NWN2, but it's very good nonetheless. The dialogue options you
choose, and your ability to pursuade others affect how encounters end; it seems there are substantial differences to how things play out as a result.
As almost standard by now you have a considerable number of potential party members to choose from and they all have their own problems and opinions. It's hard to keep everyone satisfied and I found myself switching out characters sometimes to keep them from seeing my actions.
Like most RPGs this game is a time-sink and I even feel like playing at least the beginning again with another character to get a different 'origin story'. Perhaps it is a bit too time consuming, but I was hooked indeed.