Salamanca Mk II's, I find to be very energy efficient (come on, 97 isn't too bad for a class 9 gun) and I carry a pair of them. Having slightly better range than other neutron cannons (549m vs 600m) and doing the damage of the Javelin Missile at 4.00 rate of fire, makes them a keeper on my ship. I think personally range is important too, but that's just my opinion.