Are these boots fully waterproof?

Yes. The upper and outsole are rubber and the boot is listed as waterproof, so rain and puddles are handled. The side zipper is the main spot to keep closed and clean.

How do the sizes run?

The listing shows US size 4. Barbour boots generally run true to size, but rubber boots fit best with a little room for socks, so check the store's size chart before ordering.

Is the zipper easy to use?

The side zipper is the fastening, so you step in and zip up rather than pulling the boot on. That makes them quicker to get on and off than a plain pull-on Wellington.

Are they good for long walks?

They suit errands, commutes and wet days out. The rubber shell does not breathe much, so for long hikes a lined walking boot is usually more comfortable.

How do these compare with a tall Wellington?

The short shaft is lighter and easier to walk in, and the zipper speeds up getting them on. A tall Wellington covers more of the calf in deep puddles and mud.