A properly made tiled shower can last a lifetime...how long do you want it to last? A cast iron porcelain glazed one could last a long time as well, but would need some texture to keep you from sliding all over. Some of the textures applied wear out and are difficult to keep clean. If you drop something in there, you can chip it, then it can rust. You do NOT generally want to use anything abrasive to clean these things...if you do, you'll wear the surface off. My mother has done that to her cast iron tub over the years (cleanser was more abrasive a long time ago than it is today, but still), and is a pain to keep clean because it is rough...the color is still there, and no bare metal is showing, though.
There are some solid surface ones, but they can lose their shine.
If you want to think about tiling, check out www.johnbridge.com.