Looking at the Trailer, I get the sense that they have gone for more of the 'Das Boot' feel with Silent Hunter 5. That bodes well for immersion within the game. One thing that was totally absent in SH3 and SH4 was any visual relationship or interaction between the Captain and the crew.
With Silent Hunter 5 allowing the player to play in the 'first person' mode, and if the Devs have learned valuable lessons from SH3 and SH4, then this incarnation could really work really well.
I will be fascinated to see the tech specs nearer the time of release, as I'm sure there is still much optimizing to do to the sim.