I prefer wood and almost always choose that but I do have a few clear mount. I originally bought Fox and Friends to show as a clear mount (I am a demo) so I have one block that is that size. I have since then bought Make a Monster in clear because it is easier for my daughter to stamp the little accessories stamps - and a small block. I bought 2 other sets in clear because they were ones that I liked but are more seasonal so I won't be stamping them all the time and they were the right size to use with the blocks I have.
If I buy a set that I know I am going to use a ton then I definitely want wood. I prefer the feel of it and am always afraid I am going to lose my rubber mount stamps in the mess that is my craft room.
My teeny, tiny, someday it might be a GALLERY