Often times it's a CYA! ..... whether, ironing board covers, clothes, curtains, etc.
ITA with Peckish, cotton covers are nicer for pressing blocks and smaller pieces of fabric.
However, when pressing yardage or a completed quilt top, I much prefer the silver (teflon?).
Much easier to slide it along as I mover from one section to the other as I press.
So ... what I do now is have my ironing board covered with the silver.
Then a slip-on ironing board cover that can be removed to wash or when pressing the bigger stuff.
I just use a pretty piece of quilting cotton that makes me happy to see it!
Win-Win!