[eluser]LuckyFella73[/eluser]
It can be "nicer" to group some controllers to not loose the overview maybe.
The disadvantage is that you will have to set up rules in rules.php.
Otherwise CI don't find your controllers.
But generally it's more or less a personal taste. On a site with "harcore-traffic"
it could be that routing turns out to slow the site down a bit but I can't say
how much. In most cases you don't need to seperate controllers into different folders.
It's more often that you need to seperate your view-files. But for doing that you
don't need to set up a route.