Some thoughts from a hardcore Souls player (beat both previous games twicemore into helping people beat bosses than PVP).
Atmosphere is classic Souls. If you want more story, go play Assassin's Creed.
Ability to customize your character's appearance more is awesome. My gf is a graphic designer, spent 2 hours working on my dude, and now he looks like a pissed off Jamie Lannister.
Definite Dragon's Dogma influence on the look of armor. Capes look cool.
The game is not as hard as previous games. Here's why: Estus plus Life Gems, improved online stability makes summoning easier, I feel like I'm leveling up way faster, and the game is just less devious than before. Example: I saw a preview where you had to fight this dude throwing axes as you walked up a narrow plank. In the actual game they toned that down. It just feels more like a fair challenge rather than Super Mario 3 ridiculous challenge, which I guess I miss (but I'm not that far yet).
Still with any complaints I'm having more fun than any game since the last Souls game. Playing online with other Souls heads is still sublime.