Acrylic is not as hard as the porcelain on a cast iron tub...it will scratch. You need to be careful with following the manufacturer's cleaning instructions. Depending on your environment, it can last and look good for a long time, or it could look lousy in a short time. If you, for example, lived near the beach and often came home to was the sand out of things...stepping on the sand will scratch the surface. It won't help the finish on a cast iron tub, either! If I was going to live in the house for awhile, I'd tear out the tub and replace it, preferably with a cast iron one if you can get it up there. Saying all of that, when I remodeled my master bath a couple of years ago, I put in an acrylic air tub (blows air through jets into the tub).