DS3 is better on consoles than on PC. It's not the traditional hack 'n slash it used to be; rather, it's more in style with Baldur's Gate: Dark Alliance and suits perfectly for playing two players locally.
It's definitely more focused on combat and story than the prequels, and less on the RPG part. You never get the feeling of getting stronger; the level ups does not make much sense, as the enemies scale to your level. Thus, the better equipment you find is actually just negating the enemies' stronger attributes (speaking of attributes, there are loads of them and you constantly have to check the menu to know what they do). You have hardly any skills to choose from, and they aren't very useful to upgrade. You sell items for 10% of their buying value, and you can find 10 gold in the first level as well as in the final level. Playing on Hard does not give you better loot.
Jeremy Soule is not the composer anymore, and I don't think a single song from the earlier games is used, not even the main theme. The new music is really just background music that is easily forgotten, save from a few tunes. The camera is pretty bad and you've basically no control over it.
I would still give it a 7/10, because the combat is actually really well done and doesn't get repetitive (although the game is not as long as previous entries). The story is also interesting and good enough to make you want to continue playing. Also, it's co-op after all, although to be sure to play locally because the online mode sucks. That's why it's not really suited for PC, and I'm not sure if I would play this game alone. I've not played the DLC, but it looks interesting.
Just a short review from a long time Dungeon Siege fan. If you're not into DS, I'm sure you won't be as disappointed, and the original DS is still really great