I like cast iron fixtures and just installed a Kohler Whitehaven kitchen sink, two lavs and laundry sink in CI. For bathtubs it is great material....but, they are heavy. As well, they have tremendous mass. How much hot water is absorbed by the tub to bring it up to temperature so you can have a nice bath. The tub will suck up a lot of heat. I went with the Cast limestone tub by Victoria Albert. It is our second and we have liked them.

thanks-- so what is the benefit to cast iron over acrylic? If they suck up the heat doesn't that make them bad for bathing? And being heavy, once they are installed is that a problem?
We will have radiant floor heat in the bathroom.
I was not even gonna consider cast iron till I was looking on Kohler and saw one for 800 or so dollars which is compareable to some of their acrylic. But the only cast iron in my price range is the 14 inch deep one-- which also is my other question- is a 16 inch or 17 in deep tub far better than a 14 inch one? I am a big bath person and take baths almost every day so I am willing to spend a little more and get a deeper one if it is far better

I too am shopping for a tub. Most people seem to be going with acrylic these days. They are fine, I thought, until I saw the cast stone by Victoria and Albert, the IOS and Edge. They are both quite roomy and deep, but much more expensive than others out there.

Right depth? I don't know that anyone can answer that. So many are so shallow that I am not sure what is the point. I want to float because I need for my muscles to relax. How deep is your current tub? Do you float?

I think the main differences with cast iron vs. acrylic are: Cast iron keeps the water hot longer but is harder to repair if chipped. If acrylic is scratched it can be buffed out easily and retains it's nice white finish (doesn't yellow over time like fiberglass). I think both are good choices. Also if your husband is installing the tub he will need help with cast iron because of the weight. Regarding depth, I think you need a 16 or 17" depth if you like to soak and be covered completely with water. :)