These have worked great.  I have a 5x8 rug in my daughter's room that needed to be reset every few days, and a smaller hex rug in our master that would almost just roll up on itself, despite having furniture on top of it.  The furniture just moved with the rug.  The baby's rug hasn't moved an inch, and the rug pad I cut and pieced together is holding the hex rug perfectly in place.  That hex rug has vexed me for 10 years, now I barely give it a second thought.