EDIT: I just got it. Some quick info for anyone with questions:
1. Beginning a new game, you get to pick your country of origin by selecting its flag (my country, the Philippines, is available - astig chong!
). As such, the language selected was English for me.
2. All packs from Spirit Summoner are available from the start, with an extra pack called DARK Collection 1.
3. You start off with the same character customization options as SS, but as mentioned by one of the posters here, you can unlock more stuff. It costs 500 Duel Points to change though once you've made your initial selection. It doesn't cost anything to change your uniform or duel disk though.
4. For YGO newbies: the tutorial included is the same as Nightmare Troubador, meaning it's hands-on and step-by-step. Good place to start.
5. You can customize in-game messages, like when you take damage you can say stuff and it shows on-screen. You can only choose from pre-made dialogue though.
6. Verified: SS/SC saves can't be transferred to this game. Dammit.
7. Pack Glitch from SS doesn't work. So it's back to earning it the old-fashioned way