Here's one of the advantages of 3 vs 6.
When I'm playing I like to try to clear parts in sections. So I just grabbed this as an example.
Basically just a starting point:
With 3 you can go through and clear a section and and not have it scroll away from the right edge at all. You notice you can still see the wall on the right side as you clear the first set of rows. So nothing can sneak up on you. Basically you can clear out this section and not have to look at the radar as you can see anything come on to the screen.
This next pic is set with scrolling on 6. You notice when you just want to clear this first section of lines on the bottom right that the screen moves over and you can no longer see the far right, so a mummy can sneak down the right side and you can't see. So you might get mummies sneaking up on you on the right side and have to watch the rader more not less.
I've found I like 3 because I tend to like to try clear teh levels in sections. This varies for different levels of course. Not matter what it is 3,4,5,6,7 it's all going to be a trade off to find the right strategy for each level.
But I tend to like the fact that the levels are large though too. They vary from ones you can clear in sections to ones you have to go in circles or ones that just make you come up with unique strategies. So it keeps it interesting.
