I have some friends in Colorado who built a very large deck several years ago and used the composite stuff. With a little age it looks better, and all of the fasteners are hidden. Snow glides off pretty easily and the shovel doesn't damage it. Unless I really wanted a particular look, I wouldn't hesitate to use the composites.

To me tile would be a waste of time outdoors in freezing climates. I doubt it would last through one season. It's more seen in drier, temperate climates. Depending on how you did the steps, you might pour them as concrete and lay single tiles across them (same width as the step's depth). Then you'd only have repairs every few years.