Toilets, Sinks, Showers, Tubs and Disposals - Americast or cast iron tub?

I am having a new bathroom and am going with a tile surround for the tub/shower. Since I'm using tile, I'd like a nice sturdy tub that will last. Is Americast equally as strong as a true cast iron tub? I know Americast is lighter in weight and price, but how well does it hold up? Does it need mortar under the bottom or is it just as rigid as cast (like they claim)?

Americast tubs are a composition of porcelain bonded to enameling grade metal (probably steel) which is bonded to a patented structural composite. That should be perfectly clear. LOL.
From members here that have used them, the news is NOT good. They say chipping is a big issue. Some have said they got tired of fighting with American Standard and just replaced the tubs.
We at DIY are not in the habit of badmouthing products or their manufacturers however, this is what we are hearing. Good luck with your project.

Thanks for the info, cast it is.