Ahh, toastie! The Firewalls offer eiderdown-warmth in even biting conditions and they're impressively breathable too.
These are certainly among the larger gloves out there, but Thinsulate insulation means you retain reasonable bar-feel, while a polyurethane liner ensures that, though they get quite heavy in the rain, your hands stay perfectly dry. Your fingers are separated into just two compartments to reduce surface area and so maintain heat. If you are used to using two or three fingers to control your levers though, then these aren't the gloves for you.
Sugoi takes a belt-and-braces approach to draught exclusion with both an elasticated wrist and a drawcord around the top of the extended cuff, and you get towelling on the back of the thumb for dealing with any unwanted snot. There's no extra padding in the palm but silicone rubber accents help with grip, while a small amount of reflective piping adds visibility. Magnets in the wrist tabs keep them paired-up when not in use - nice touch.