There are many companies out there doing "rebath" systems. That is, putting an acrylic overlay over the tub and walls. It's "pretty" but I've seen mold/mildew issues with these systems at times. Not ALL installations mind you, just some. Also, I dont care for the "squishy" feeling of the liner due to the silicone used to hold it in place. All that being said however, it usually is cheaper than a new tub/surround installation and there are times that money is an issue of course.