Lighter projectile is moving faster giving it more energy and less loss over distant traveled.

If your going to be shooting longer than 200 yards the 7mm rem mag would provide an edge, closer the bigger lead of the .35 certainly wouldn't hurt. That said as long as you pick a solid constructed bullet like you mentioned I personally think it is wash, either will topple a moose. I haven't met a moose yet that did to well after placing 160gr .284mm bullet into his vitals. If your going to be at risk of coming face to face with a Griz then the whelen would be a better choice, other than that buy or use whatever floats your boat and go hunt!