Dragon Age 2 is very fun.
I've beaten it already. This game is fun depending on what you expect.
The combat is faster, smoother, but it's a bit easy playing on Normal. You will want to push it to Hard if you want to keep the tactical feel to it (pause and play).
The game can run up to 70 hours if you look for all your companion's gear upgrades, do all the companion quests, do all the side quests, hunt down the different crafting items, etc.
You can beat the game in 20 hours or 70 hours, depends on how much you do.
Great game, but not as good as the original, IMO.