I replaced my Muck Arctic Pro with Norfin Klondaik boots. They’re an upgrade in every way. The Mucks just didn’t keep my feet very warm after a few hours on the ice, and they’re heavy as heck.
I believe the issue was how tight of a seal the Mucks create around the calf. There’s no air exchange whatsoever, so my feet would sweat and stay damp. I tried every sock or sock combo known to man. The Norfin allow my feet to breathe because of their cloth inner sleeve. I could tell the difference right away. I got home to damp socks with Mucks and dry socks with Norfin. This could also explain why some people love Mucks and other don’t: the size of their calves and the seal (or lack thereof) created.
The Mucks are good boots still. I use them for snow blowing or launching my boat after the docks get pulled, because they pull on and off easily and they’re perfectly waterproof, but they’re disappointing ice fishing boots.