A few things pop out when looking at the entire sector (minus the domain that I still haven't mapped); there's a fairly solid line from the top corner up in Republic space to this corner. There is a small break where they have to piggy-back off of Cartel worlds to continue their run and a few Cilindarean worlds, but they can make a pretty solid run diagonally across the entire sector.
The Berns are not in as strategically envious a position. The Cilindarean Arm breaks up their main territory in the north from colonies in the South. There are a handful of allies here and there sprinkled through that territory, but not enough to get from one side to the other. The Cartel is also broken up into a few "islands" that are not readily reachable without passing through somebody else's territory. The Cilindareans have a strategically viable position, with only a few isolated systems here and there, though. Outremer is, of course, separated from the rest of the Empire, but that's to be expected given the name that it has; it's a far-flung Crusader state, not a traditional colony in the traditional sense (although that will be seen more in the last domain when I get there.
I'm not going to post the full sector map again, because I'll just do that when I get the last domain finished.