I have been using Zagg IS for longest times and I pretty much used it for all of my electronic devices. I have been very happy with IS. Of course, I got full body kit for both my wife and my iPhone 4. Here is the problem: the new iPhone 4 is made of glass on both front and back. I noticed that during the very warm and humid day(yes, it is east coast thing), the IS got very soft and they peeled of very easily. It came off when you put the phone in/out of the pocket. It came off if you lay the phone flat on any surface that IS decide to adhere to. It came off too often(more so on the back side), it ended up collecting too much dust particles and lost its adhesive. At the end, the IS is useless. This has never happened with any other devices I used IS with??? Did anyone experience this? I didn't have this problem with my old iPhone 3G.