I wear Blundstone's and really enjoy them. Very comfortable, looks nice, easy slip on, and can pass for normal off-duty to limit the items in my overnight bag. We can expense footwear so every ~2 years I can refresh them on company money. As much as I like the idea of a fine quality shoe that can be redrafted (own multiple Allen Edmonds), the fun mix of fluids on the ramp seems to just cause havoc on anything that touches them. They have insulated and special sole options if you frequent places like Anchorage often. Also they have a Pro Program if you're a veteran, pretty good discount.

Maybe when I'm a CA and never have to do the walk around, I'll get some RM Williams.