I've had two pairs of the Northwave Celsius boots. The first pair I bought back in 2008, and I used them for several winters commuting in NY happily. It tends not to drop below 20 degrees F in NYC in the winter, and I found them to be great around freezing temps.

I got a second pair of the extreme version of the boots a couple of years ago. They are much warmer than my old ones, which is great when is really cold, but not so great when it's warmer. Both sets are very waterproof.

They are both pretty stiff soled, walkeable but stiff.

I stopped riding clipless, or I'd still be using them.