Thanks for asking! I somehow felt that the new Tuff-Luv cover was smaller and lighter than the Bookeen cover, so I checked.
Weight:
Bookeen 123g
Tuff-Luv 111g
Dimensions H x W x D:
Bookeen 19,2cm x 13,4cm x 2,0cm
Tuff-Luv 19,3cm x 12,3cm x 2,6cm
So Tuff-Luv is actually slightly lighter, but nothing actually noticeable, I think...
As for size, both have almost the same height, Tuff-Luv is narrower (due to the Bookeen's bend being on the side), and Tuff-Luv is thicker (due to the clasp and stand on its backside).
Hope this helps!