scm wrote a review of Mammut Extreme Siam GTX Glove on January 25, 2011
First of all, the backcountry.com description of these gloves is inaccurate. It states that they have a removable liner, however this in incorrect, they do not. What they have is something called Gore-Tex 2-in-1 technology, which allows you to slide your fingers into one of 2 chambers in the glove. One chamber is warmer and insulated, and the other chamber basically puts your hand so that the warm chamber is on the back of your hand, giving your fingers more dexterity but less warmth. One would assume that the back of the hand would be twice as warm in this use case.
The outer shell of the glove seems really well constructed, as is typically the case with most Mammut products. The stitching is top notch, and the leather is very soft and supple, and has reinforcements just where you'd want them.
I can't speak to the warmth of the gloves. I am probably going to return them since what I really wanted was a glove that is a shell with a removable liner, which is what I thought that these were.