Chad,

I haven't tried Muck boots, but for what it's worth here's what I use:

A pair of Asolo hiking boots if it's 40+ or if it's colder and I will be doing a lot of walking without too much sitting. They are the most comfortable boots I have owned and they required no break-in at all. Any more, if shoes isn't incredibly comfortable when I try them on in the store, then I don't assume that they will get better with age. The break-in is too hard on my feet and takes too long! They are a bit expensive, but I feel very much worth it.

For colder weather, especially sitting on stand, I recently picked up a pair of Irish Setter (Red Wing's sports division) Yukon 1898 on sale. They have 600 grams of Thinsulate and are very warm and comfortable. I've only had them for about a month, but have been able to walk a couple miles in them without any problems.