In my opinion, having used both quite a lot I reckon the Montane is better if you're planning something low activity wise but want to stay warm, but is just to hot to be worn whilst exerting yourself. The Buffalo on the other hand, is just cool enough that if you are a chilly person you can get away with wearing it whilst exerting, but if you stop you may end up needing an extra layer (though with the zips buttoned up it's usually fine).
As previously stated, I don't think one is better than the other, they're suited to different styles of use imho.
I've used the Montane as a replacement for a sleeping bag (long story!) and it was actually quite cozy.
Interesting thoughts from the other threads. There is one very good reason I carry a GPS as a group leader. If I (the main map reading dude) go down and need medical attention, I'd quite like my group to know where we are exactly! It's a lot easier to teach a teenager to switch a GPS on, wait 3 minutes and read the numbers that appear on the homepage (although they've probably already got a grid from their Iphone by then admittedly!)
Franco - applying the KISS principle there, good to see! Though I would say that generally the term "multifuel" is used for stoves that burn more than just specialist liquid stove fuel (eg diesel, petrol), whilst "omni-fuel" seems to be the vogue term for a stove that will burn fuels that are liquid at room temp/pressure as well as accepting gas cartridges of some description. (seeming coined by primus)
The mighty pocket rocket has a known issue, which is to do with (iirc) the length of the pointy thing that pushes open the seal on gas canisters. IIRC it is a fraction of a millimeter shorter than the standard "pointy thing", and, as such, sometimes fails to open the valve. This can sometimes be countered by ensuring the stove is screwed on 'kin tight.
Not an issue exclusive to pocket rocket as my Mrs's "generic" cheapy stove has the same problem, which is exacerbated as the area around the neck of the cylinder cools with the gas expanding, so the stove fades out over time.
Steph - as gkis says, you may be better off with something "country" by design. Any thoughts on a budget? The "country" brands do tend to be a bit more expensive, but several (Musto particularly) have very good outlet stores that do some pretty hefty discount. My home jacket (for knocking around the farm, particularly in winter) is a Musto Woodland, which is probably not what you are looking for (a bit hot I suspect!), but as an example I picked it up from the Musto outlet in gloucester for £120, which is something like 50% of the RRP.
If you're looking down the standard outdoors product line, then yes, Jack Wolfskin do some alright jackets in your wanted style. Don't feel obliged to go "3-in-1" from the same manufacturer, most of the YKK interactive zips will work happily with any manufacturer's jackets (inner and outer).