I *love* these.  They are crazy comfortable, warm, easy to wear in cool and cold weather.
A few things - Be careful when you remove the liner.  The first time I did it, I broke the button. (Crocs replaces these for free)
Also, the white liners get funky FAST.  Even if you wash them they still quickly look worn and matted.  They do not sell the liner separately so you can't update them.  Next time I'll get Black.
Regarding how very warm they are, that tends to not be the case after one season of hard wear, now that the liner is matted and been washed twice they are not overly warm and can be worn in spring.  They're still comfortable, but I'd prefer the option to buy a new liner!