I've recently had a quote from a plumber to replace our grotty old shower tray and enclosure (long quadrant 1200mm x 800mm). As the old tiles are horrible and the grout is failing, he has quoted for either replacement tiles or shower wall boarding. This shower wall boarding is a new one on me, so I've googled it and it looks as though it's much easier to keep clean. Does anyone have this in their bathroom? Is it preferable to having the walls retiled?