Worn both in the filthiest weather and the Montane is superior – the design is better thought out in most every aspect (cuffs and hems have a slimmer fleece which works better, pockets better thought out, better ventilation, reinforced forearms) and is much cheaper (you get the hood included with Montane).
I really think the Buffalo would have been unbeatable if they had tweaked the design – but they didn't. The Montane does soften a lot and pack down a bit when used and washed.