I have three chair mats.  Each of them folded in half.  And, over time, each has cracked along the seam in the middle.  So, when I found this one-piece mat, I was interested.  Now that I have had a chance to see and use the first of these to replace a cracked mat, I decided to order a second one.  The first one seems to stay in place on my carpet, lets the carpet show through and  looks nice.  I haven't had it long enough to determine how well it will last/remain without cracks but so far I like it enough to order a second one.