I bought this jacket near the end of the East's ski season ,so it was used in conditions between 35 and 70 degrees(yes,very odd for the end of the season).Initially I thought it would be cold when I first tried it (cold walks with the dog in the morning before heading for the mountain and near freezing),but much to my surprise I realize that my body heat quickly and effectively warmed me up without over heating.It also did a great job(in the morning while spring skiing) of breaking the wind and maintaining my body heat while dressed very lightly underneath in anticipation of the later day ramp up in temperature.It is a first rate product that fits,functions and looks great.I have to say that the fact that the product was tested on Everest says a lot also.If it didn't do it's job correctly there,that jacket would have been burned in the trash before it ever made it home from the Nepal.

I bought this to replace my bulkier Patagnia softshell. It is the lightest, most streamlined softshell I have seen. The arms are long enough, and the hem long enough, that it does not leave you exposed when climbing. The hood can be adjusted to fit well with and without a helmet. One problem I encountered was with the drawstring cinch in the back of the hood. It is not very robust, and I broke it trying to adjust the drawstring with gloves on. The shell uses two materials, both of which are light and breathable, but one especially so. This probably would not appeal to some, who want more water protection. But there is a definite trade-off between waterproof-ness and breathability, and I side with breathability.

I wore this on Mt. Blanc during a summer ascent and was quite warm, even when the wind kicked up. It's durable, it sheds rain well (I've worn it in severe downpours and stayed bone dry), and to echo the other reviews, it is much warmer than I could have hoped. Overall, it's well-built and is on a par, in my opinion, with any of its higher-priced alternatives. Best of all, it looks great in summit pics and can even be worn around town.

This jacket is the bomb. First of all, it looks good, which is saying something since many functional jackets don't look all that nice. Secondly, I wore this thing while sleeping in my car, and even when the temperature got down to about 45 degrees, it kept me warm. The jacket is so light, and I didn't expect it to offer much warmth at all, but it totally proved me wrong. It's comfortable, and it never makes me feel sweaty. I liked it so much, I bought a woman's version for my wife.

This highly anticipated new First Ascent line has put everything one should expect into a soft shell. From the ergonomically contoured sleeves to the accessability of the pockets while wearing a pack. I took this jacket on a hike the week I got it one month ago. After shedding it to my pack once the morning chill was gone, I didn't think I would need it again. However, the weather forecast was wrong, and rain moved in on me. I wasn't sure how long I would stay dry since soft shells are really only water "repellent." This jacket beaded water like a fresh coat of wax. I stayed dry, and never felt sweaty as the breathablity of the Mountain Guide Jacket was superb. Normally I find a hood to be a con on a soft shell, but I was thankful it was there on that day.