Take the description literally - the INSERT is waterproof, but the SHELL is NOT waterproof. The material on the outside of the thumb soaks up any water immediately on contact. The rest of the shell is water repellent, but the seams are not sealed. They do advertise the mitten this way, so I only have myself to blame. I should have read more closely.

The lack of a waterproof shell reduces their versatility. With the inserts in, they are TOO warm for most "normal" activities. One reason I was attracted to the mittens in the first place was the removable liners, hypothetically meaning I could use the shells alone in cool/rainy conditions, the shell with liner gloves in sleet/33F rain, or use the mercury liner/mitt for really cold temps. Sadly, since the insert is waterproof and not the shell, they aren't effective for anything but bitter cold.

I also found the "trigger finger" liner to be uncomfortable. Putting my index finger in the main section with the rest of the fingers helped, but that was also a bit uncomfortable because the liner wasn't designed for that.

Honestly, these mittens deserve at least a 3-star rating, probably 4 stars. They were designed for bitter cold, and as everyone else has noted, they do a very good job of keeping your hands warm. If you are looking for an alternative to the Alti Mitts for extreme temps and mountaineering, these might be a good bet (but I can't say from experience because I'm not into that stuff).

I rated them this low because I was just so put off by the non-waterproof shell. It seems rather pointless to have the insert be the waterproof part. You can't even use the insert unless it is below ~10F, and at those temps you don't need to deal with rain and sleet anyways. I guess I just feel a bit mislead is all, and they weren't what I expected.

I bought these for Alaska riding after wearing my old Mountain Hardware beaters past the "one more season" point. These gloves are very warm and waterproof even on sleety Southeast Alaska days spent on the mountain. Goatskin shell is NOT waterproof, but my hands haven't gotten wet at all, and have stayed warm down to about 20 degrees so far. Liners are easy to remove. I haven't had a problem with them being too warm. The trigger finger doesn't bother me (I don't even notice it) and the shell is very grippy, if you need to grip stuff. I like the long gauntlets for keeping out the powder. All in all, a quality glove half-way into their first winter. Worth the money: I'd buy it again.

Got these for really cold skiing and backcountry days in Colorado. So far this winter I've only had to use them once, but they were nice: extremely warm, and they seem really well made. My only complaint is that they run really large. I usually wear a large glove or mitt, and the large in these is way too big, which makes them a little clumsy. I may try to trade them in for a medium, but I'd like to find somewhere to try the medium on before I pay shipping to send these back.

I just inaugurated my BD Mercury Mittens high-mountain skiing at Finse, Norway last weekend, and am very pleased with them! First day was cold (-25C) but due to these mittens I hardly noticed. Relatively good breathability although I was toasting inside by the time we reached the peak. Next day was slightly less arctic (-10C) but with high winds. That day I (as usual) donned a lighter pair for the first part of the ascent and switched when the wind-chill set in further up the mountain.

I’d say this is a first class mitten in terms of cold and wind protection. Good proportions, good protection around the wrist and easy to use with ski poles. Straps can be adjusted with mittens on. The trigger finger adds to dexterity, but don’t expect miracles; I could plot the GPS with the thumb only, and normal zippers can be hard to operate. Opening snowboard bindings etc will however not be a problem. Although I have no intention to take out the inner liners except perhaps for drying, it seems a bit fiddly to put them back in place.

I immediately fell in love with these mittens. I endorse that they must be “built for the deepest, coldest days of winter” and they will be my pair of choice for the harshest days out skiing and snowboarding. On wormer or wetter days I will however use another pair.

Peter Anderson has a good point about the mitts not having a waterproof shell. However, I think if you are going to be skiing in dry, Utah blower, or Montana cold-smoke, these would be just fine. If you're not dragging your hands in the snow, and it's not a warm, soppy day with a chair-lift dripping on them, you'll be fine.
I haven't had a chance to use mine on any wet days yet, but in fresh powder on cold days, they keep your hands toasty.
I like mittens that come up over my wrists and jacket, so that I can take 'em on and off easily. The Mercury Mitts are easy to use when hands are cold, and they warm fingers right up when you get them back on.
The liners aren't easy to pull in and out as there is some pretty solid velcro attachment, but I don't use the liners alone.
They could potentially grab some moisture from the snow when it's warm out, but you don't need these for days that aren't bitter cold anyway.
I also put snow seal on the stitching and places where I thought water might condense. I have had no problems with moisture coming in yet. The shell does a good job of keeping the liners dry as far as I've experienced.
So, I think as long as you are not skiing Cascade concrete, and wet coastal snow, these will be fine.

Great mitts. Can't say much else. My hands tend to get pretty cold and they were sweating with an air temp. of about 10F and a wind chill below zero. Bomber.
Note: they run slightly large.

I always have cold hands no matter what. These have been terrific - hands always warm & dry - perhaps the only complaint is -- too warm.

I have had these gloves for over year and they are the warmest gloves I have ever had. My boyfriend was jealous so I bought him a pair. I would highly recommend these gloves.

I bought the 2007 model to use in Canada. The temperature is very cold at our mountain. My fingers were frigid each day from skiing with gloves. These mittens solved that problem. Now my hands, especially the fingers, are always warm. This is a very good mitten at a very good price. I thoroughly endorse this mitten.

Hella-warm! It would be almost impossible for your (or anyone's) hands to get cold in these. Like most other expedition style insulated mittens, they have sufficient (synthetic) insulation in a separate liner, and a waterproof shell. Trigger finger is cool, but it is still pretty difficult to handle anything small in these mittens, but that is the case with any exped style mitt. Great quality construction as well. I dont see why you would pay 150+ bucks for other style insulated mitts when these are 85 and just as warm. You could use these for 8000 meter climbs in my opinion. I have used these in 0 degrees with 60mph winds and my hands were not at all cold. Maybe a bit heavier than Down insulated mitts, but trivial.

I bought these for winter camping in Michigan(with my Boy Scout son) and after reviewing dozens of others (including the Alti), I figured that at 20% off of the $86 price tag, if they aren't all that warm, then I'll give them to a young family member whose fingers don't get as cold as mine do. As it turns out, I cannot imagine a warmer, more comfortable pair of mittens. With the trigger finger design and overall warmth, these remind of the leather shell, lambs wool-lined mittens that my dad wore in WWII as a Merchant Marine sailing at times during winter storms that required heavy-duty warmth.

Since, like everyone else, I want or need some dexterity at times, I simply ordered a size up and where liner gloves (O.R. PL400's) beneath and I am literally covered. My liners slide in and out with ease and mate perfectly with the Mercurys. For now, I can only imagine that my particular combo will keep me comfortable well below zero (Farenheit).

Also a tip/trick, if I only need the liners for a time and don't want the mittens exposed and dangling from their "idiot cords", I crafted a way to keep the mittens warm and secure inside my jacket by adding Nite-Ize size #2 S-biners to the loop ends of sport eyeglass Chums, then attaching the mittens to the biners and hanging all this from around the collar of my base layer. This set-up makes my coat a little puffy around the chest area, but it keeps me and the mittens warm and protected from the elements.

The bottom line is that the Mercury mitts are incredibly warm and well-made at any price. To Black Diamond, thanks for a product well-done, but please continue to keep the price down, I still have my wife and kids to buy these for.

What can i say i have suffered from cold hand syndrome ever since i started riding and these things are the BOMB, kept me toasty riding Jap backcountry for a month the season just gone and have been able to brave the discusting aussie backcountry (wet slush) recomended to anyone.
Only downside is using GPS and other such equipment is near impossible, so i thing i'll be purchacing some BD gloves for those aplications.
Enjoy the parth on your hands coz it just wont stop