We're using composite which feels like some sort of metal. (Azek Trademark Reserve,www.bostoncedar.com) It was pretty expensive, (more than I spent on the decking and framing)but I wanted something solid that didnt shake and flex and was also maintenance free. The vinyl looks nice from a distance but seemed very flimsey to me.

I used vinyl railing for my deck. It came with aluminum supports in both the bottom and top and is very solid. To see pictures check out the short review I did after my deck was built. http://decksummer08.shutterfly.com/

I like the vinyl my Mom has, but it's very flimsy. You can't lean on it, so we have to put furniture, plants, etc. in front of the railing. If you could reinforce it with the aluminum, it should work well. It looks great, just not sturdy.

It depends on your budget. A good composite rail is typically much more than vinyl.

I much prefer the look of composite over vinyl. I chose to use Timbertech Radiance Rail. It was more than all of the and framing lumber and materials