I used the Rab Drillium jacket in moderate winter conditions for hiking, backpacking and cross-country skiing in the Catskill Mountains of New York, to elevations of about 4000 ft (1220 m), for a total somewhat in excess of ten days of use. Weather ranged from moderate snow to occasional mild rain, and temperatures from about 15 to 32 F (-9 to 0 C), give or take five degrees.

I used the Drillium as my primary shell from January to the middle of March. I usually run somewhat hot during intense physical activity, and this was generally a mild winter. In consequence, my base layer was a thin long-sleeve merino shirt or an ancient Hind DryLete cycling shirt that I like; over that I wore the jacket, and this was generally sufficient for the conditions, so far as my torso was concerned. I would start out feeling cold, but after moving for a few minutes, even in windy weather, I felt comfortably cool (the ideal for winter hiking). When stationary, usually after summitting or when stopping to eat, a couple of times I wore a warmer insulated jacket over the Drillium. Since it isn't bulky, this was a perfectly feasible proceeding.

I don't usually wear a shell constantly except on the coldest of winter days, but I didn't find that the Drillium posed much problem with regulating moisture (a serious matter in winter), and in consequence I wore it non-stop (this also let me test how well it let moisture escape). The breathabilty of the eVENT fabric seems more than adequate to me, though not, naturally, a complete panacea.

I still found that, after a particularly strenuous ascent, or some especially hard skiing, my shirt would be a little moist; but then, that would likely be the case even without wearing the jacket. Since the conditions were generally dry, I could regulate my temperature to some extent by simply opening the front zip. I haven't yet tested the jacket under truly rainy conditions. Nor have I used the hood more than a couple of times, as I usually wear a warm hat in winter when conditions require it, and there's been no rain to fend off. I intend to examine these aspects in the milder and wetter two months to come.

I very much like the way the sleeve ends seal over my gloves, enabling a seamless and snow-proof junction. The waist also seals well with its drawstring. I was disappointed with the closure of the neck of the jacket, when fully zippered. The high collar promises (and, initially provides) good protection, but I found that invariably the zip would slip down several inches in a few moments. Generally, I used a neck gaiter over the collar, though if the zip had stayed put, I would not have needed it. The problem was not fit—the neck does not feel tight—but simply that the zip does not hold its position. This could be prevented with a locking zipper, or perhaps a "zipper garage" created by the addition of a tab with velcro tabs at the top of the collar. This was my only real disappointment to date with the garment.

The wind resistance of the jacket is very good. Several times during this test period I was out all day in moderate winds with gusts of up to twenty knots (28 km/h) or so (based on local forecasts, as guessing actual windspeeds is a notoriously fallible process). Even on exposed summit areas, I felt well protected against the breeze, though temperatures (before factoring windchill) were well below freezing. Based on the conditions I've been exposed to so far I would judge that the Drillium's ability to deflect wind is on a par with, or superior to, most windshirts and jackets I own.

The eVENT seems pretty durable so far. With the exception of a couple of outings on groomed snow on skis. and two shorter day hikes, I was wearing a pack at all times, and the shoulders so far show no evidence of wear from this. I have even used the jacket for some moderately hard bushwhacking without any misadventures (although this is probably pushing my luck). The one mischance I've had with the jacket was a very tiny leak of a jojoba oil/Teflon preparation used on waxless skis in transitional temperatures. A few drops from a bottle in a pocket spread like crazy to create a sizable and ineradicable stain, still all too evident after two washes with a sports-specific detergent.

This doesn't seem to affect the utility of the jacket in any way, although I note some very slight evidence of delamination in this area (eVENT is a three-layer fabric laminate). I will be curious to see how this affects that section of the jacket in wet conditions, and I do wonder what it implies for long-term durability, since it seems to be the oily component that has caused the problem (Teflon itself is pretty much inert). I've spilt cooking oil on myself at least once in the past while backpacking, and this fabric seems to sop up oil, with a small amount creating a stain of surprising proportions. This strikes me as a potentially messy issue. When backpacking, sometimes greasy stuff just happens!

Laundering (beyond the fact that the stain did not wash out) was straightforward. I steam-ironed the jacket afterwards as suggested. The laundry instructions suggest periodic treatment with a DWR treatment, but before I do this I want to see how the fabric performs in rain without this step.

The pockets are extremely spacious, and on a couple of shorter (four to six hour) hikes in milder conditions, I stuffed them with food bars, spare gloves, a headlamp and other odds and ends, and left my pack behind. This makes me look a little pregnant (a friend's remark), and is certainly not recommended winter technique, but it felt liberating.

The Rab Drillium has proved a very useful and durable shell in moderate winter conditions. I have found the breathability to be sufficiently good that I can wear it continuously, an asset on days when there's constant snowfall. I have some reservations about the way the collar closes, but this can be worked around with the use of a neck gaiter, which I tend to use many days in winter in any case. The eVENT seems to be rather vulnerable to oils, but then that's bad news for most fabrics.