I have never used either of those. Is the W&N transparent or is it more translucent?
The only two clear gesso brands I have used are Art Alternatives which is not really clear but has more of a translucent milky look to it and Tri-Art which is significantly more transparent / clear than the Art Alternatives brand, though it is not as clear as a clear acrylic medium.
I have only used the Liquitex one. It’s pretty transparent but gritty. I only used it once when I wanted to paint over something I did with coloured pencils. I sanded it to make it smoother.
I have used Liquitex Clear Gesso to paint oils over acrylics. The tooth helps in that case. I know of another painter that uses the Clear Gesso to create tooth for pastels. If you do not want the tooth, I wonder why matte medium would not work. Gary