I have an extra Ugg insole in my boots. I wear them often, and feel like they have great support, but, mainly because of having the extra insole in them. It probably gives my foot more to sink into for a more severe contour. I do not have high arches.
I have one pair of Ugg boots (the one with the extra insole) and one pair of Bearpaw. The Ugg has significantly more support overall than the Bearpaw, but an extra insole could be put into any of these styles of boots.