I bought these to use on a wall, not the ceiling, and I'm painting them so it won't matter if they are plastic or metal. If they were going to be up on the ceiling, I think they could pass for metal without painting. These are flexible plastic, not the Styrofoam, so they are much sturdier.
I ordered these tiles for my bathroom ceiling to replace 1x1 foot squares. I had a grid - I taped the squares to the ceiling with double-sided tape and then stapled where there was overlap and the staples were covered. Cut around the light and a section of pipe easily. Looks 100 times better than the previous material - beautiful!