Those who want to know about the additional content of Tales of Xillia should read this:
http://www.gamefaqs.com/boards/616012-tales-of-xillia/66894136/753456421
SCENARIOS EXPLORATIONS SIDEQUESTS COSTUMES SKITS
-At the beginning, you can select two different scenarios, each devoted to one of the two main characters. They change some sets of events rather than the whole plot and you can enjoy the game even playing only one of them, even if it's advisable to play both in the Jude-Millia order if you want to get the most out of the story. Useless to say, this does provide a nice boost to replayability.
-102 side quests side events are available during the game; some are fetch quests or mob hunts, others are story events meant to deepen the party's characterization.
-Three types of skits are available: long (traditional) skits, short skits (think the Dragon Age banters while you explore) and battle skits. The game has some 241 long skits.
-Bigger maps, sometimes with multiple levels; you can jump and climb at set points to reach new areas. The maps themselves are organized in the same way as Tales of Graces f to provide an interconnected set of areas; so, while there are indeed linear areas (just as in Vesperia and Graces), you won't find a FFXIII-like corridor from the prologue to the final boss, thankfully.
-Warp function to avoid backtracking.
-There's a Quick Save option.
-60 of Aifread's Treasures (Aifread being Tales' legendary pirate, for the ignorant landlubbers) scattered across fields and dungeons.
-A generally sleeker presentation, with Ufotable at the helm and one of the best Sakuraba OSTs.
-Rotable camera, third person view instead of the fixed camera employed in all previous 3d Tales of games.
-Xillia's shops level up during the game, either by buying items or by improving them using materials found in the fields. Those improvements carry over to new shops of the same category.
-4 costumes (2 for Milla, 1 for Jude, 1 for Alvin) are in the game, plus one free DLC with recolored outfits. The other costumes are available as paid DLCs.
-65 Attachments (the items used to customize your heroes' appearance).
-An Ex Dungeon.
-An Arena (no cameo battles, be warned).
BATTLE SYSTEM ARTES WEAPONS
-A fusion of CC and TP, with the CC-like AC points being used for attacks and TP being employed for traditional Artes (it's somewhat a GracesVesperia combo, if you will), providing longer normal attack chains and more combo opportunities.
-You can swap your party members during battles (I don't mean your controlled character - you can bring people in and out of battle like in FFX as soon as you have more than four characters).
-Aerial combos are back, if you missed them in Graces.
-A customization system centered on a spiderweb-like scheme, the Lilal Orb, that works in a similar way to FFX's Sphere Grid.
- New Link Artes that let you coordinate two characters in order to make unique moves (not all characters have them, and they can have some issues when at least 3 gamers are playing together).
-Each characters has unique skills you can trigger during combat. Please see this post: http://www.neogaf.com/forum/showpost.php?p=39690960&postcount=799
-One Mystic Arte per character, with a Jude+Milla Dual Mystic Arte
-The Fell Arms.
-Optional bosses.
-Joke weapons (rewards in the Arena)
-Grade shop (grades are organized differently than Graces f, though)
-Five difficulty modes (Easy, Normal, Second (Moderate), Hard, and Unknown)
