I spend a lot of time outside in the winter season photographing athletes participating in hiking and mountaineering activities. I like a jacket that keeps me warm as, despite Scotland not having the coldest temperatures, it's easy to get dangerously cold outdoors.
During the Scottish winter season, the mountain thermometer commonly fluctuates between -5 and +5 degrees C, which is not cold in itself but when you add on strong winds and freezing rain hypothermia can be a real threat.
The world's best insulator for outdoor activities (if you discount animal hide and fur) appears to be goose down. If you're operating at high altitude or in the cold regions of the earth many experts say there is nothing better. Scotland's maritime climate however can kill down feathers in a matter of minutes and what was once a nice, fluffy, warm layer of clothing becomes an un-insulating soggy mess - even beneath a water-resistant shell - and dangerously ineffective.
Whilst down is still useful for e.g. sleeping bags and very cold temperatures, synthetic insulation such as Primaloft is a more sensible approach for insulated clothing in maritime climates (being generally lighter, warmer and more functional than fleece for the same weight and more robust than down). Over the years, I've had a number of synthetically insulated jackets, including a Patagonia DAS parka, a Cloudveil Enclosure jacket and a North Face Redpoint Optimus (and a Wild Things belay jacket, two Berghaus Infinity Pros, a Berghaus Asylum Belay Parka, a Haglofs Barrier Zone Hoody, a Patagonia Nano Puff, a Rab Generator smock and a Rab Xenon X Hoody). I've not outworn them all - I tend to trade jackets in needlessly when I think something 'better' comes along - but I reckon I've used the type long enough to pass opinion on them.
My current 'I always take it' jacket for Scottish winter (which I will wear out as it is excellent) is Mountain Equipment's Citadel jacket. It has kept me warm during countless photo shoots in the Scottish mountains, in Patagonia, below freezing in Spain and the Alps, and on a cold ledge during an unexpected winter's night out.
For static warmth in damp and cold conditions I'd suggest the Mountain Equipment Citadel is perfect. It’s by far the lightest insulated jacket you'll carry (a size L weighs in at 890g) and it's far too warm too walk in but when you need to stop for any length of time in winter weather and retain body heat for a good length of time, it's excellent.
What I like about the Mountain Equipment Citadel jacket
200g Primaloft One is very warm
Elasticated back helps stop cold spots
Thick insulated hood
Large inside pocket - I place a Nalgene bottle filled with hot water in it for a ready-made hot water bottle
Repairability - mine's has a big 'L' shaped rip on one of the front pockets courtesy of a careless dry cleaner in Punta Arenas in southern Chile. Down insulation would have exploded everywhere but I fixed it simply with some McNett Tenacious Tape (an excellent product worth a review in its own right)
The original Mountain Equipment Citadel I bought was small in its size, which I thought was odd for a belay jacket (climbers wear these type of jackets over all their clothes for warmth at a belay). Mountain Equipment's customer service however was excellent and I received a new one by return
What would I change?
Both velcro wrist straps have ripped off, presumably due to poor stitching
I'd remove the stretchy wrist gaskets - they get soaking wet and take longer to dry out than the jacket
When not wearing a helmet, I'd prefer the front collar of the jacket to be taller when zipped up so it covered more of my face (A Haglofs Barrier Zone Hoody jacket I have - sadly discontinued - has the best hood I've ever had on an insulated jacket)