It was very much an “explore and see what you can find” sort of experience.

This needs to come back, this is what's lacking in these mmos. It doesn't even need to be a strict sandbox like Ultima, it can be class play and dungeon raiding like everquest or wow, but at least make the world alive and gives players a reason to go out and explore. It's amazing, we have all this game tech and yet developers still want to make games where you follow the quest markers. Shit like this is why I wish games didn't have such huge budgets and developers could get away with smaller more independent teams making games they actually want to play, rather than chasing focus tested market trends.