I've seen all sorts of people on forums dump hatred on DA2 in a seemingly irrational manner, so I thought what better way to find truth to these accusations than to play the game itself? So having played the game myself, here are some completely unbiased confirmations that I can make here. Bear in mind that I'm playing the PC version, so maybe some of these things may not apply to the console versions.
Combat has not been dumbed down in anyway. Also, DA2 is HARDER than DAO (I've been playing on Hard and Normal, the REAL difficulties that you should be playing on).
I don't know why people keep talking about how everything has been dumbed down. You auto attack by right clicking on enemies, you set tactics for your non controlled party members, you can pause the game in order to deliver commands to your companions strategically, and you can use skills and abilities by hotkey or mouse. Same as the original but faster and more fluid, pretty much. Also your character doesn't shuffle around awkwardly when trying to attack certain enemies even when you right click on them like in Dragon Age Origins, so that's a plus for me. And yes, this game is harder than the first. Abilities have been remade somewhat and enemies will swarm you like crazy, so you'll be pausing a lot more often in order to get yourself out of stickier situations. The bosses are actually difficult, too, especially now that you can't just chug all four types of Health poltices on your character anymore. Now you only get one type of Health potion and one type of Stamina potion and both of them have long cooldowns.
There is inventory management in this game as well as being able to customize the appearance of Hawke.
I don't know where people got this assumption from, but I can say for certain that it came out of their asses. You can indeed customize the appearance of Hawke and equip items on him or her with a wide range of armor, helmets, rings, amulets, belts, and weapons. The only difference is that armor can't be equipped just by your Strength stat but sometimes by both Strength and Consitution which apply to heavy armor or Cunning and Dexterity which apply to light armor. You can also equip your companions with amulets, rings, belts, and weapons but not their default outfits, but is that really a bad thing? Can you really picture Morrigan wearing a First Enchanter Robe or Isabella wearing heavy plate?
The game was no more linear than Dragon Age Origins and Awakening were.
Basically, the gist is that there are still rival factions to choose between, a wide assortment of main plot quests that can be undertaken at any time, and loads and loads of side quests to complete. Dragon Age Origins gave the player the illusion of having freedom by giving them the ability to change companions into whatever armor sets and weapons that they liked, but in truth there wasn't much freedom at all. Leliana starts out strictly as an archer, Sten a two-handed swordsmen, and Morrigan a mage. Yeah you can equip Morrigan with dual daggers and Sten with a sword and shield but that wouldn't be very efficient, would it?
Now, to prove that I am indeed unbiased I'm going to confirm some things that did genuinely disappoint me in Dragon Age 2.
No more persuasion or cunning options in dialogue.
A minor complaint, but still bugged me a bit. Running into special kinds of dialogue options that offered better rewards or unorthadox outcomes were always kind of a nice thing to have.
Side quests consist mostly of talking to people and killing things.
Pretty self explanatory, and was also a problem that Dragon Age Origins had.
Companions weren't quite as dynamic or memorable as Origins's companions were. Also you can't converse with them as often.
I don't know. To me the characters you get in Dragon Age 2 have the potential to be very compelling and interesting but they just haven't stuck to me yet. I think they could have gotten the player more attached to these companions if they would let you converse with them more often.
In short TLDR, Dragon Age 2 is a fairly decent RPG that is, in most aspects, just as good as Dragon Age Origins. Also that most of the hatred that DA2 gets is completely irrational. Seriously, 2/10? Only a completely broken game with absolutely no redeeming qualities would be worthy of a score that low. 7-8/10 would be more fair in my opinion.