Which would you prefer?
1.) A smaller but seamless world.
2.) A larger world that would require fast travel between different areas.
Agreed. 'Larger regional worlds' are a dime a dozen. And based on what i've seen and read about Witcher 3, it's going to fall into the same category. Even TES has touched down in it, truth be told, with things like Shivering Isles and Solsthiem.
Personally, i'd rather the current approach, a smaller, scaled world which exists seamlessly. I'd even like to see that seamlessness expanded to include dungeons, caves and cities, but it'd settle for what it is now.
That's not to say i like the status quo. Technology is progressing, and so is processing power, and the worlds should be getting bigger. Skyrim was what, 15 square miles? The next should be at least 20.
A smaller, seamless world.
Fast travel fundamentally removes me from the game, not to mention the fact it leaves chunks of whatever province it's set in unexplorable for no good reason, to account for travel time.
A bigger video game world than The Elder Scrolls III: Morrowind, The Elder Scrolls IV: Oblivion, and The Elder Scrolls V: Skyrim combined with absolutely no loading screens . That's what I want to see from a open world sandbox RPG video game.