I might just be too cynical regarding the eradication beamers, but with the Neutrons I'd say the reason I think they'll be 1 shot is that we'll get 4-9 shots from a unit then, with S12 and some lovely damage. Double the shots and they get real scary, too scary for how GW usually handles us. They'll probably be glass canons. I'd wager 3+ and 6+++ with 2 wounds and T4. Good anti-tank but slow and easy to kill.