The Wolf looms were designed to be portable, so they are lighter weight. Rug weaving generally requires a very tightly tensioned warp and heavier beating than other types of weaving. With a Wolf loom, you may find that the loom tends to move when beating a rug. You can work around this by placing weight on the cross brace between the rear legs.
The November/December 1994 issue of Handwoven magazine article “Weaving Rugs on a Lightweight Loom” by Gail Madden has helpful information.