WMB reviewed both your options in this months mag. In case you havent seen it I'll try and do a v quick paraphrase. Excuse the spelling.
NW – zip+laces, medium insulation, great price, stiff upper means its not right for everyone. Cabon sole at performance end, screw in toe studs, slightly slippy hard compund thread, decend wading performance, no separate top sealing and some testers found stiff upper unconfortable around ankles. 3.5 stars.
Shimano-Velcro straps, medium insulation, leapt up in price, still reckon toughness and thermal comfort make best value all round winter boot. Sole not as toothty as some, medium compound grippy. Open design means no clogging. Solid feeling not penguin still for walking. Big roomy insulated offers unhindered circulation. Paddle proof. Tall neoprprene collar helps stop drip seepage. Can be a squeeze to get on. No studs. Makes a great misery beating cold weather investment. 4 stars.
btw Lake MXZ302 was the overall winner.