When I started playing Traveller, I created my own sector. I went with 3x3. Imagine my consternation when GDW said "hey, it's 4x4 silly". Well, to this day, MTU still uses 3x3 sectors. Didn't have a lot of money in college, so MTU was the only way to go if I wanted to play (well, referee mostly). What is this "Third Imperium" you speak of? 
