1. About double the content, so what XV 1 + another XV1 in terms of story and content but the roster obviously isn't as big since the first one had over 60 characters, that'd be hard to add as many characters.
2. They have a mode without levels so that you can play any character and face anybody, better tracking of your melee and range attacks, new dashing abilities to catch your opponent, no spam, stamina break that lets you do full combos on your enemies. Pretty good, it's completely revamped. Also if you're on console, the game doesn't look like vomit anymore and it runs at 60 FPS.