I can say this though from what I've seen. The intro is addicting.

I actually don't know... personally I think it may be bigger than Fallout 3, but what breaks the feeling of it being better is the loading from place to place. Actually I am fairly confident it is bigger than Fallout 3.

It probably has more game space than fallout 3, but it isn't a full sandbox like Fallout 3. It is more sectioned large world spaces opposed to one large world.

I played this game solo till about level 20 with a soldier. I found it fun enough to warrant the purchase, but last night I played splitscreen with a friend and we both made new characters. Level 1 to 19 for both of us in one gaming session, it was ridiculously fun. I forgot how much splitscreen makes games awesome. The duel system is so much fun, we probably spend a quarter of our time dueling eachother. Everytime we got a new weapon, or upgraded a cool skill we would duel to try them out. Epic.

Ive invested somewhere around 10 hours into the game now, and sit at level 18 i think. And im still enjoying it. There's some really bad ass enemies, literally (Bad Ass Brink!) :D

And i really enjoy the co-op and tactical skill builds. And i still feel like its a solid 80-85 game. There are some bugs and annoying parts when doing co-op, atleast when you invite people who have finished certain quests that others haven't. Other than that, its a solid game recommended for purchase.