Is the ThermoBall Lace Up boot actually waterproof?

Yes. It has a waterproof DryVent membrane plus a non-PFC DWR finish on the recycled ripstop upper, so rain and slush stay out.

How warm is it compared with a down boot?

ThermoBall Eco is synthetic insulation that keeps warming even when damp, which down does not. It is warm for city winters but less insulating than a heavy down or pac boot in deep cold.

Does it run true to size?

The boot is described as secure-fitting with a traditional free-floating tongue. Try your usual size first; the lace-up closure lets you adjust the fit over the instep.

The boots as sold, with laces and the top webbing pull loop already attached. No extra insoles or care kit are included.

Can I wear it in deep snow?

It handles wet snow and slush well, but it is a low-profile lace-up boot, not a tall snow boot. For deep drifts or long exposure, a taller insulated boot is the better pick.

How does it compare with the Sorel Caribou or Columbia Bugaboot?

It is lighter and more sneaker-like underfoot than those boots, with a softer faux-fur collar. The Sorel and Columbia options are heavier and warmer for extreme cold.