Differences between cloth, fiberglass and silicone baking mats?
The key difference from my perspective is cleaning. Silicone is the easiest material in my kitchen to scrub clean, with the possible exception of stainless steel. Cloth is very far down the list.

Also, depending on the texture of the cloth, more food will almost certainly stick to the cloth, unless it's sealed with something, in which case what is it sealed with? And how is it sealing the fiberglass in?

I use the kind with a thin grid of fibers inside the silicone. It adds more stability and lets the overall thickness be thinner for better heat transmission, compared to a plain silicone silpat. As long as I don't use it as a cutting board, the fiberglass stays safely inside. It does add a very slight grid texture to the bottom of loaves, but it's barely noticeable and doesn't look bad at all.

The pyramid kind, which would reduce food contact and increase drainage and airflow, sounds like it would be good for specific applications, but not something I'd make a batch of cookies on.