I do have the radtech cloth. I used it on my old MBP. I have had it three years now. I will start using it for my new rMBP with out the keyboard cover. The cloth alone gives the lid enough clearance for the lid to close. It also makes a great cleaning cloth. The material is perfect
I have a thin microfiber cloth that came with an old Toshiba portege laptop... Fits perfectly and I always place it between the screen and keyboard of my MBP when I close the top.
I do have the radtech cloth. I used it on my old MBP. I have had it three years now. I will start using it for my new rMBP with out the keyboard cover. The cloth alone gives the lid enough clearance for the lid to close. It also makes a great cleaning cloth. The material is perfect