I used these in my trip to Alaska, in the winter.
Pros:
  Great insulation, I never had cold feet.
  Very light and comfortable, despite of the size.
  Enough space to wear thick merino wool socks and toes heaters (which I did not need).
  The insulation can be easily removed.
  Kept my feet dry, even when the snow was covering them.
  Easy to put them on and take them off.
  Decent grip.
Cons:
  Super bulky. It will take a good chunk of your suitcase! I had to wear them on my way to Alaska and back.
  I live in Southern California, I won't be able to wear these here.
  Because it is very rigid and high, it is probably not suitable for long hikes, climbs and descents. I did several short hikes and it was rubbing against my calves (it just felt a bit awkward). I have big calves.
Other thoughts:
  These boots are great for being outside waiting for the aurora borealis. If they were smaller and more flexible, they would be perfect.