Is excellent! I went for navigation my first playthrough out of habit, and it was exactly what I'd expect (go faster, transverse jump etc). This second playthrough I've gone with sensors, and it is, at least in the early game so much better. My fleet travels at burn 9/18 instead of 10/20, but I can 'go dark' and still travel at 8 speed. I can see everyone before they see me, do sneaky type missions, raid anyone's isolated fleets to my hearts content, travel in triple red ping systems with no worries... its great.
Its probable that when I have a fleet with capitals I'll swap over to navigation. It is better for long haul, and once the player can stomp things/has outgrown sneaky missions, speed is better. But for now, this is just great.