Fiberglass walls are generally more affordable, lightweight, and easy to install, but they may not be as durable and long-lasting as acrylic walls. Acrylic walls, on the other hand, are more expensive but are more resistant to scratches, chips, and other types of damage. They also have a smoother and more polished look. Ultimately, the choice between fiberglass and acrylic shower walls depends on personal preference, budget, and specific needs.