Martin S.wrote a review of NRS Boundary Sock on November 9, 2011
So, got them, wore them, loved them
Started the hike (Orderville Canyon, Zion) out in wool socks, until the first major submersion was needed. Changed into the NRS socks. Had further on warm feet, despite swimming, and wading in icy water.
The socks have a seal which in my case did good in not letting too much water in (i.e. blowing them up). As these go higher than some other products, more of your leg stays warm.
In terms of bulk, these are not more than the thick wool socks I had on initially.
Make sure you dry them properly, as with all neoprene items. And in winter, use them on your bike commute during those wet weather days.