TOP Roof, Anyone?

Just wondering if anyone has a TPO membrane roof, and if so, if you could comment on your experience with it so far, including how expensive it was and who installed it. We need a new roof, and TPO sounds like the way to go (environmentally friendly, better insulation, fewer leaks, longer life), but for the relatively small roofs we have in NYC, maybe it’s not cost effective?

And didn’t it used to be rooves, not roofs??