i have the alpha burlys,i have used them in a summit viper they worked fine.
mine are the 1200 gram if you put a thin pair of poly propelyne socks on with a pair of good shamino wool socks there good to about 20+ Max my feet sweat bad walking in them the propelynes help wick the moisture
i heard the Woody muck boots are better for warm and comfort,i ain't complaing but when your feet get cold the hunts over