This was my first pair of Baffins and I will never buy a different brand of winter boot. They are awesome. Baffins is a Canadian brand of boots so the measurements on cold rate are done by Canadian standards. -40C is the same as 200gram insulation for American boots.  If you need more than the normal 200g insulation look at Baffins -50,-60,-100C boots for more insulation as you need it. Most people are fine with -40 boots like these and this pair as worked out very well for me. Baffins are made with a synthetic rubber sole that grips well w/o every being squishy. The tread on these is great and much better than other brands offer. Because these are boots made for walking in the snow they have a very strong structure to the bottom that allows you to stomp all day w/o hurting your feet unlike  the way that some other non winter boots would be. I found this to be a great feature as I find myself rolling my feet on pavement and stomping in snow.  They are made with very strong waterproof nylon on the outside, I have yet to have any wet feet no matter what winter condition I am in.  They are very very light weight. I would compare them to the weight of a tv remote.  All of my Baffins are very light weight but rock solid. Don't let the physical weight fool you, these are strong studrly boots that will protect your feet from whatever winter throws at you.  The boots stand up on their own, I do not need to sit down to put them on. The insulation lining in the boots is removeable if you have to wash it, but I have yet to need to. Maybe if I fell through the ice I might need to, but mine are always dry and odor free so it has not been an issue. A note: liners are specific to the boots you cannot get a -40 pair of Baffins and place a -70 liner in they will not fit. The strings on the boots do not need to be tied or undone when taking the boots off, I set mine once and left them alone.  If you are walking in some place where you feel that you need to put on some type of snow/ice traction on the bottom of the boots you can do so with these boots, IF you order the traction devices a size up as these boots are wider than most boots. Even though these are tall boots, I can still wear them under a pair of boot cut jeans. I would not be able to if my jeans were not boot cut to start out with. There are other Baffins boots -40C that are available that can be worn under most jeans. I have no problem wearing these under boot cut jeans, or under ski pants I have also worn regular jeans tucked into these boots without problems. This was my first pair of Baffins and I now own several pairs for different purposes and bought them for several family members.